can vitamin d intake affect an already normal mestrual cycle?

by Leslie

I loved all the information on your website and my family and 1 started taking vitamin d because of it. An osteopath clinic nearby told me over the phone to start with 50,000 I.U./for 5 days then 5,000 day to maintain and 20,000 I. U./day for 5 days then 1,000 for my 7 year old.

We've been doing this for roughly 1 month and my cycle is 9 days late and I have no symptoms of pregnancy--3 tests showed negative.

CAN VITAMIN D AFFECT A CYCLE THAT IS REGULAR? Once or Twice a year my cycle may come a up to a week early, but otherwise every month it usually comes on time to the day. I have been late about 4 times in 13 years. I am nervous about how I may have affected my hormonal balance and how to correct it. I would GREATLY appreciate your help.

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Vitamin D and the Menstrual Cycle...
by: Kerri Knox, RN- The Immune Queen!

Hi Leslie,

Well, there have been NO comments about anything having to do with the menstrual cycle in the literature. And in fact, there is anecdotal evidence that Vitamin D IMPROVES fertility, and one study on Rats that intended to show the toxicity between Vitamin D3 and vitamin D2.

The study gave 'toxic' doses to two groups of rats. The rats given these toxic doses of D2 all died, the females given the SAME dosage of D3 all got pregnant!!

So, my FIRST thought is that you might be pregnant! Home urine tests are not always accurate- particularly if you drink a lot of water and are not using first morning urine.

So, if you are worried about it, then go see your doctor and get a blood test. Otherwise, how old are you? Could you possibly be going into menopause and be missing your first period?

And even if you are missing one period and are not pregnant, it's unlikely that anything has been 'damaged'. Sometimes we women just get off cycle. While unusual, just get it checked out.

And I hope that you don't take this wrong, but your level of anxiety over this makes me think that you might benefit from some extra magnesium. And indeed, one of the Side Effects of Vitamin D is that it uses up more magnesium. And those who are already slightly magnesium deficient can get 'pushed over the edge' to have some symptoms from that.

So, I would recommend getting a blood test to make sure that you are, indeed, not pregnant. And two, take some extra magnesium by following the guidelines on my Magnesium Dosage page.

Let me know what happens!!

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System

D3 & Cycle
by: Anonymous

I am experiencing the same thing-my cycle is always VERY regular. Since taking d3 I have now skipped my monthly. I'm 29 yo(not menopausal) and absolutely not pregnant.

Being that d3 is a hormone, I would assume that these symptoms can't be that far fetched as to there being a correlation...

If it were a hormone, you'd think that...
by: Kerri Knox, RN- The Immune Queen!

You said that since it's a hormone, it makes sense that it could do that- except that it is Not a hormone, it is a PRO-hormone.

Another prohormone is cholesterol and since eating a lot of cholesterol wouldn't affect your menses, then....

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System

d3 affecting my cycle
by: Paula

I have always been on time with my cycle but have been taking D3 for 2 months and since then I have experienced lateness of periods and a change in the cycle across both months.

An unexpected benefit of taking D3 is that my circulation seems to have improved - i have worn socks to bed every night for as long as I can remember and I now can't wear them because my feet are too warm. I don't know whether this is usual or not.

Vitamin D
by: Anonymous

You mentioned that one of the side effects of Vitamin D is that it uses up more Magnesium.

Well, I found some side effects of Magnesium Deficiency, one of which is change in Menstrual Cycle.

Random Magnesium Deficiency Symptoms:
Sudden change in behavior (like relaxed and confident people may become high-strung)
Unusual craving for salt or chocolate
Tenderness in the breasts (in case of women)
Changes in the menstrual cycle (in case of women)
Marked apathy in behavior (especially in case of anxiety and panic attacks)

I also experienced a change in menstrual cycle while taking Vitamin D, and am wondering if this could be the reason. I've been experiencing hair loss, and I read somewhere that Magnesium Deficiency can also cause hair loss.


by: Kerri Knox, RN- The Immune Queen!

Hi Sarah,

Interesting thought. All of the symptoms of magnesium deficiency that you outlined are right on. Unfortunately, there are no studies showing that magnesium deficiency affects the menstrual cycle (usually causing PMS and the symptoms that you mentioned, but not LOSS of menstrual cycle).

That is not to say that's not the reason that you and others are experiencing this and I'd be really interested in your experiences if you do take magnesium along with your vitamin d and see if it corrects your menstrual difficulty.

Again, unfortunately, this is something that there are SO few women experiencing that no one is going to ever do a study on, so it'll be up to you to let me know if that changes things and I can let other women know and we can see over time if that really is the case.

So, please let me know if you end up taking magnesium and how that ends up affecting your cycle...

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects

Found something else:
by: Anonymous

Aside from the Magnesium Deficiency theory, I found an interesting article today:


Vitamin D may reduce breast cancer risk through an effect on steroid hormones in cycling women. We conducted a study to determine whether there is an association between circulating 25-hydroxyvitamin D (25(OH)D) and estradiol and progesterone in young women.


Volunteer women aged 18?22 and not using hormonal contraceptives were recruited during summer and winter. They provided demographic and lifestyle information and a blood sample. Women recruited in winter gave a second sample after taking vitamin D supplement for 4 weeks. There were 101 women sampled during the luteal phase (1?14 days prior to the start of the next menstrual period). Generalized estimating equation linear regression models were used to examine the relationship between 25(OH)D and estradiol and progesterone.


Per increase of 10 nmol/l of 25(OH)D, progesterone multiplicatively decreased by a factor of 10% (95% CI 5?14%, p < 0.001) and estradiol decreased by a factor of 3% (95% CI 0?6%, p = 0.04) after adjustment for age, body mass index, ethnicity, season, alcohol use, smoking, and physical activity.


Higher levels of vitamin D may reduce progesterone and estradiol, providing a potential mechanism for reduction in breast cancer risk from increased vitamin D exposure in young women.
Keywords Vitamin D - Estradiol - Progesterone - Women - Luteal phase

Financial support: Canadian Breast Cancer Foundation Ontario Division.

Looks like this study saw a decrease in Progesterone and Estrogen in women taking supplemental Vitamin D. Just thought it was interesting that they mentioned Vitamin D effecting a woman's hormones. Any thoughts on this?


altered period after vitamin d
by: Anonymous

Since the birth of my second child I have been EXTREMELY fatigued around the time of ovulation all the way until I finally get my period. That's a good 2 weeks!

Fatigued to the point where my skin would feel heavy on my face, I could barely get through work, I just wanted to nap whenever I was home-it was bad. I went through a slew of blood work and started speaking with a therapist for fear I was battling with post-partum depression...

I was freaked out! The only thing that came back abnormal was my vitamin d. so i started a vitamin regimen of Vitamin d3, fish oil (known to improve mental health) and vitamin B12 (just because i thought it couldnt hurt!) well-by the end of the first month of this regimen i felt a difference overall. i've been taking them for a little over 2 months and all symptoms have improved HOWEVER, i had my daughter 18 months ago and have been on a 28 day menstrual cycle TO THE DAY! (naturally, no birth control pill or any other hormones). my first period after taking the vitamins my period was 2 days early!!

i've NEVER been early in my life. the second period was 7 days late! it was so strange! i took 3 pregnancy tests! then when i got my period it lasted 9 days! so there is definitely some correlation if others are experiencing a change in menses.

after reading your previous comments i will look into my magnesium level-is that something i can have checked via blood work? thanks for the info.

Don't test for magnesium...
by: Kerri Knox, RN- The Immune Queen!

You CAN test for magnesium, but it's essentially worthless if it comes back normal. Please see my page on Magnesium Levels to see why.

While I'm not disagreeing with you that the Vitamin D may have something to do with your cycle, you also just had a baby and the post partum period is VERY often characterized by changes in the cycle. That sounds the most likely culprit...

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System


PS: If you found this website helpful, please consider using the
Easy Immune Health Product Store the next time you purchase your supplements online. Your support allows me to keep this site running and educating as many people as possible. Thank you!

by: JCinVT

I'm so relieved to have found this site with all these discussions! I started taking D3 about a month ago and my period is usually 24 days on the nose but I am a week late now and started to freak out because I am 42 and do not want anymore kids! I took a pregnancy test and thank God it was negative but I still haven't gotten my period and the only thing I could think of that I've done different is the D3.

I'm wondering now if it will ever be regular again or if I need to take magnesium as I read on some of these posts. Maybe this site is really old, but if anyone can shed light on this, I'd appreciate it.


My cycle changed too
by: JackyClaire

I'm glad I found this site. I started taking D3 a couple of months ago and I was normally 28 days on the nose. Then for the past 2 periods I've been 21 days !!!

I'm 50 and thought it was menopause starting, but now I think it's the D3.

D3 and affect
by: Tina


Just came upon the site looking for other info on D3.

Kerry mentions that there's no potential for a study on the vitamin affecting menses as it just doesn't appear to be a side effect.

Does it strike anyone else that here are a number of women with similar reactions in a relatively short time in just this blog?

The push for taking the vitamin is really recent for the general public, with TV PSA's as well as print and radio media PSA's about taking it, resulting in far more women taking it as a supplement in just the last year, so that now more are seeing this reaction, where before it was 'rare'? The potential for even more women being affected is higher as the media push goes on and women (also giving their children) will be taking OTC doses without benefit of a professional's advice.

Perhaps a study *should* be done!

Kerry, with just these women all reporting similar responses and probably more to come, exponentially there must be thousands more out there that haven't found this blog. With you being in the industry, wouldn't it be prudent to talk to those who look into these types of matters and see if you can't get them to do a study?

I wonder if or what men taking the extra D's reactions might be as they're less inclined to talk about changes in their bodies. What about children being given adult doses?

These are studied..
by: Kerri Knox, RN- The Immune Queen!

Hi Tina,

While there has not been a formal study of this, do remember that every single study on every drug or nutrient records every single side effect reported- whether it is dry mouth or death and everywhere in between.

So, while there have been no studies done on this subject exactly, there have been hundreds of studies done where this was NOT reported as a side effect- not even by one woman in any study that I have seen!

That's a LOT of studies that had no problems with this reaction! Therefore, in a way it already has been studied and shown to be not a problem- and therefore the reports that I get on this website, I feel truly ARE extremely rare.

Besides, I have not heard back from any of these women that it has been a lasting problem. Are women just missing their cycles by a few days? Missing their periods for a cycle or two at the beginning of treatment?

Or are these women having lasting permanent changes that have led to infertility or that required surgery?? I've not had one single woman write in to tell me that her period was permanently altered and she became infertile...

And in fact the opposite it true, there have been many reports (and animal studies have shown this as well) that some women may improve their fertility taking vitamin d!

If you or anyone that you know was made infertile or had any serious lasting changes to their cycle that caused infertility, required surgery to stop bleeding, etc. I would be interested in hearing about it...

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects


PS: If you found this website helpful, please consider using the
Easy Immune Health Product Store the next time you purchase your supplements online. Your support allows me to keep this site running and educating as many people as possible. Thank you!

vitamin D and missed period
by: Anonymous


I too am so glad to have discovered this site. ..Also wondering the dates of these posts (today is Jan 8,2011).
My period has never, ever been late. Ever! I am 42 years old and the mother of two young children. I started taking D3 almost 2 months ago. I am now almost 2 weeks late and have been trying to figure out what is going on. Vitamin D is the only thing I have done differently. I am definitely not pregnant.

I lost my husband to cancer 1 1/2 years ago and am acutely aware of my health and any changes. I must say I am relieved to hear of others experiencing the same thing. I will try taking magnesium and stop the vitamin D and see what happens with my cycle. I have been taking 4000 iu's per day.

My Naturopath had tested me and I was deficient. Occasionally I would get 8000 iu's a day simply because I might get two drops instead of the one 4000 iu drop. Maybe this is too high of an amount, but everything I have read seems to say one can not overdose on vitamin D in these amounts....?

I will write back again and let you know what happens.

Thank You!

Period still late!
by: JCinVT

First of all, this is Jan. 9, 2011 - the first time I wrote was a month ago. I was late again this month for my period by almost 3 weeks and I stopped taking the D3 last month after I found this site.

I'm thinking maybe it takes a while to get out of my system. I'm also now having some issues with my breasts and I never had before...I'm wondering if this is related because on the bottle it says that it helps breast health.

The doctors have found calcifications in one breast and having been monitoring it but now need me to get a biopsy because they are concerned. I wish I'd never taken this vitamin cause it seems to have screwed me all up!

I suspect that you have magnesium deficiency symptoms
by: Kerri Knox, RN- The Immune Queen!

Hi JCinVT,

I'm sorry to hear that it seems like you're having problems after you've been taking the vitamin D for a while. However it does seem like you have some magnesium deficiency symptoms that were probably affecting you in many ways before you started taking the vitamin D. I encourage you to read my page on Signs of Magnesium Deficiency page in order to see if you indeed do have any of the signs of magnesium deficiency that I suspect you do have.

in particular, your description of having calcifications in your breasts is definitely a sign of magnesium deficiency. Any time anyone has calcifications anywhere in their body it leads me to believe that you're severely magnesium deficient and probably happen for a long time.

if you go to my page on Magnesium and Vitamin D you'll see that vitamin D can induce magnesium deficiency symptoms as well and make an existing magnesium magnesium deficiency even worse.

Also, I was wondering if you had started taking any magnesium as I had recommended to the people in the thread before you? It seems as though that's likely your biggest problem. Space I would encourage you to get more information about magnesium from the bookMagnesium Medicine as it is one of the most comprehensive books about magnesium that I know of and I think that you would benefit greatly from the information that is contained within it.

Taking large doses of any one vitamin or mineral is not recommended as there is always a balance between vitamins and minerals and taking large doses of one temper off the balance of any of a number of others. That's why I always recommend taking a multivitamin and mineral supplement if you happen to be taking large doses of vitamin D.

I encourage you to get more information about magnesium and let me know if you have any questions.

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects


PS: If you found this website helpful, please consider using the
Easy Immune Health Product Store the next time you purchase your supplements online. Your support allows me to keep this site running and educating as many people as possible. Thank you!

Magnesium Oil
by: Kerri Knox, RN- The Immune Queen!

Hi again JCinVT,

By the way, I was also thinking as long as you get all clear from your doctor that your breast space problem is just a calcification and not something more serious, you may want to consider using a product called Transdermal Magnesium Gel.

it's possible that you can reduce the calcifications in your breast by rubbing the gel directly into the calcifications on a daily basis. It can be irritating to some people, so you may want to wash it off about a half hour after application, but if you're breast problems truly are calcifications and nothing more serious than the magnesium could possibly reduce or even eliminate the calcifications in your breasts.

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects


PS: If you found this website helpful, please consider using the
Easy Immune Health Product Store the next time you purchase your supplements online. Your support allows me to keep this site running and educating as many people as possible. Thank you!

Thanks Kerri
by: JCinVT

I appreciate your response and I will definitely read all the links you provided. I am having a biopsy soon so as soon as I'm cleared, I will start taking magnesium. I'll keep you posted. :)

Me too
by: Miss T

Just adding my case - I took vitamin D3 for one month and found that my period which all my life has been a regular 28 cycle changed to a 26 day cycle. After several months with no D3 it returned to a 28 day cycle, but then I took D3 again. I had only taken it for one week before my next period (2000 IU a day)and my next cycle was back to 26 days. I took magnesium and calcium with the d3 - pretty sure no magnesium deficiency. Maybe noone reported a change in cycle length as they weren't asked about these types of changes or maybe they did not make the connection. Many people are not that regular anyway. I was confused about my cycle change but only now after my second bout of taking D3 and reading this have I made the connection.

Me too!!!
by: Farmgirl

I never usually leave comments....but this is just too coincidental! I too am late with my period by 12 days after taking a 50,000 dose of Vit.D3 the day before my period should have started. The Vit.D is the only change I've made in recent weeks. This may not be a big deal for some, but I have literally NEVER been late before.

And I've been keeping track since Jr. High :) I'm 35, and my family is complete with 3 kiddo's. Needless to say, I've been a little freaked out about the possibility of being pregnant (even did a home pregnancy test today: negative)...and now am VERY relieved to find this sight and to hear that there may indeed be a correlation between high amounts of D and the menstrual cycle!

Lasting Period
by: Michele

Oddly enough, I have the opposite problem of the others who have posted. I had blood work done and was found to have a vitamin D deficiency. I was put on 50,000 IU once a week.

I am on a birth control pill. Since starting the vitamin D, I have had a period. Prior to this I was having a normal 4-5 day period 4 times a year.
Any thoughts on this? Thanks!

Earlier periods, Longer periods
by: Anonymous

3 months ago I started increasing my vitamin d3 supplementation to between 8,000 and 10,000 IUs/day. I also have a long-standing vitamin regimen that includes 750 mg.- 1,000 mg. of magnesium.

I normally have very regular 28 day cycles with 4-5 days of bleeding, last day very light. First month after increase of D3 was normal but the past two months have been 24 day cycles with 8-11 days of bleeding, with the extra days being light.

The first 4-5 days were extra heavy flow than I normally experience. I am convinced this is due to the D3 and I am going to reduce the amount I take and see what affect this has.

by: J.C.

I'm 20, and a college student. for the past year I've been keeping tract of my period and its been predictable for a while now. Two weeks ago my doctor prescribed 50,000 IU vit D and I've been taking it weekly.

However my period was suppose to start yesterday? I'm freaking out, but I'm super glad to see that women have been experiencing late menstrual cycles.

But I'm really scared. I can't be pregnant now. And I'm terrified of taking a pregnancy test, how long should I wait before I should consider it? I know my body very well when it comes to my cycle, but I haven't had any normal pre-period symptoms.

Can someone who has this problem please be a bit more elaborate about how long it took to regain your period?

Vit D
by: Anonymous

I was also diagnosed last October 2010 with a Vit D deficiency and was prescribed 50,000 iu of vit D 1x/week. I did not get a period for the 2 months I was on it. My Internal medicine Dr then pulled me off the vit D and retested after a month.

The vit D was back to low and then I got my period back after being off the vit D for a month. I was then prescribed 50,000 iu 2x a week. I once again did not get a period for the 2 months I was on it. I was retested again after being off the vit D for a month. My vit D was low again. I got my period once again after being off the vit D. I have now been to an endocrinologist and a gastrointestinal Dr. No one will help.

My periods have been regular my whole life, I am 30 and have no kids. I have been on the same pill for the last 2 years. I work a physical job and I am outside a lot. Where can I go? Obviously I am not the only one with this problem but I am sick of being tired from a low vit D! My Magnesium and Calcium levels were also normal.

If you're 'sick and tired' then take vitamin d!
by: Kerri Knox, RN- The Immune Queen!

If you are 'sick and tired' from low vitamin d, then take vitamin d and get your levels up! Missing a period for a few months is NOT DANGEROUS. Why don't you get your Vitamin D Levels up to 'optimal', as I recommend on that page, and see if your periods return. I will bet that they will once your body's equilibrium returns to normal.

Also, GET OFF THE PRESCRIPTION VITAMIN D!!!! PLEASE, people, stop taking that stuff and tell others to get off of it. Please read my page on Prescription Vitamin D. Also, as I mention on nearly every thread where people experience problems with vitamin d, if you are 'just' taking high dose vitamin d, you are asking for problems.

You MUST take vitamin d with a HIGH QUALITY (not drug store brand) multivitamin and mineral supplement such as Beyond Any Multiple. Vitamin D WILL deplete you of:

Vitamin A
Vitamin K

and very possibly other nutrients. If you are 'marginally deficient' in any other vitamins, then vitamin d is going to bring this out and lead to problems.

This is a starting point for you. Get off the prescription, get on a GOOD quality multivitamin and mineral supplement and get your vitamin d levels up. I'm betting that you are more deficient in many vitamins and minerals than you think. Just because your doctor hasn't TESTED you for vitamin K, vitamin A, B vitamins, etc. doesn't mean that you are sufficient in them. It only means that you haven't been tested for them- there's a big difference....

Kerri Knox RN

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects

Same thing has happened to me TWICE!
by: Anonymous

This is the only real discussion I can find on this topic and am relieved!

I was on a round of Vitamin D (50,000IU 1X a week for 12 weeks) in the fall and my periods were late by 2-3 days every month for three months. I am normally VERY regular. It actually seemed to make the beginning of my periods last longer if that makes sense. It took days of spotting for my period to start.

Well, I went back to the doctor for some blood work a few weeks ago and am Vit D deficient again! So, he prescribed another round of 50K IU/1X week. I took the first round on Friday, my period was due on Sat/Sunday and the same thing is happening again. It's taken from Saturday until today and I am still just spotting. If it's anything like it was last time, my periods will be longer now. I know I am not pregnant - I've had two negative tests and no other signs point to pregnancy (temperature, etc.) and I am spotting red.

I am planning on trying to conceive a second child starting next month, so any talk of Vitamin D causing a change in progesterone levels and possibly affecting the luteal phase scare the devil out me! I already have a short luteal phase - 12 days (the bottom of normal), so I don't need any help shortening the cycles!!! I need mine longer!! I normally have a 30-31 day cycle, ovulating on day 20(I use a fertility monitor and I chart - so this information is fairly valid).

Anyways, I think I am going to discontinue the use of the prescription Vit. D and take my prenatals and try to get my Vit. D from sunshine and fortified foods.

Thanks for all the great info!

Me Too - Vitamin D has changed my cycle
by: Anonymous

I was prescribed (50,000) vitamin D once a week for 6 weeks, I started taking it last month after my normal period. This month my period is taking forever to start..Very light spotting for the past week, is it going to show up normal or is it going to stay really light and go away?I have always been exactly 28 days, heavy first day lighter until 6th day end. The vitamin D is the only thing I have changed. I am 35 and had a tubal ligation 15 years ago, so I am not pregnant. I only have two more weeks of this high dose vitamin D then I am supposed to start Vitamin D3 2000 units. I know you say that it doesn?t hurt to have an irregular period, but it is very hard to make plans when you never know if your friend is going to be there or not!

Does it get better with time or does everyone have unpredictable cycles as long as you are on vitamin D?

Get off the prescription
by: Kerri Knox, RN- The Immune Queen!

As I've said before ALMOST NO ONE has irregular cycles on vitamin d to begin with. For the next part, please GET OFF THE PRESCRIPTION. Prescription vitamin d is SYNTHETIC and it is NOT the Vitamin D3 that occurs naturally in your body. There is TONS AND TONS of evidence to show that synthetic nutrients and hormones, including vitamin d2, cause more problems than the naturally occurring nutrients and hormones.

Next, if you are having any problems when you are taking vitamin d, I EXPECT people to have problems if they are not taking the other 'cofactors' that go along with the vitamin D: magnesium, vitamin a and vitamin K are the ones that are KNOWN. Are there ones that are NOT known yet? I'll bet that there are so I NEVER EVER EVER recommend that people take vitamin d without a HIGH QUALITY multivitamin such as Beyond Any Multiple ALONG WITH even extra magnesium if they need it- and the VAST majority do.

Vitamin D 'uses up' other nutrients -and nutrients are NOT DRUGS, they are NOT designed to be taken alone, so do not treat them like drugs and take them alone.

Next, it is EXTREMELY unlikely that you are 'always' going to have irregular menstrual cycles due to the vitamin d. It's MORE likely to be fixing whatever PROBLEMS that are in your body, whether you know that you have these problems or not, and it will go back to being regular after it's made the major adjustments that you need. If you are vitamin d deficient at 35 years old, then it's likely that you've BEEN vitamin d deficient for a VERY long time. That leads to loss of bone, muscles weakening, nervous system irregularities, and a WHOLE bunch of other problems.

It may take time to fix these problems that you've been bringing on for decades. Relax and allow your body some time!! Not one person here has come back to say that they were permanently damaged from the vitamin d causing temporarily altered cycles- and in EVERYONE here, I suspect it's occurring because of OTHER severe nutrient deficiencies and is a WARNING that there are a lot of problems in your body from not taking care of yourself properly for many years....

Last but not least, why are you planning on taking 2000 IU's after taking 5 weeks of your loading dose? That is NOT the proper maintenance dose, nor is it appropriate to put someone on a maintenance dose until the level is sufficiently high that it needs to be maintained! Please read my page on Vitamin D Therapy and follow the step by step instructions to bring your vitamin d level up to optimal...

Please listen about vit D and menstrual cycle
by: Anonymous

I have found this website very interesting but find your resistance to the idea of a link between vitamin D and the menstrual cycle so frustrating. I have had similar experiences having gone onto a vitamin D and calcium supplement and then found my cycle changed from a 28 day to 21 day cycle. This reverted when I stopped the supplement for other reasons. There is evidence of a link between vit D and estrogen, though it does not seem to be entirely understood, according to the websites below. Though they do not state that taking vitamin D supplements will change your cycle, if it is affected by or affects the relevant hormones surely that is then a possibility?

Neither of your articles show ANY relationship
by: Kerri Knox, RN- The Immune Queen!

So, first of all you need to read both your articles again. You used them to make your point that there is a relationship between vitamin d and estrogen that is not well understood, then you pointed me to two articles that do not make a single connection between estrogen and vitamin d or menstrual cycles and vitamin d.

I've read probably over ten thousand STUDIES, not articles by lay people but actual studies, on vitamin d and have not seen one single one mention even the slightest relationship between vitamin d and estrogen, nor has a single study reported even a single woman having an irregular menstrual cycle due to vitamin D.

Now, I'm not resistant that you ARE experiencing what you are experiencing. You ARE. I'm not going to deny that.

But there is a big HOWEVER....

HOWEVER, many women have written in saying crazy things like vitamin d has made their period late when this is the first time it's been late and they are sometimes only ONE SINGLE day late when they have written in in panic saying that it was the vitamin d that did it- and some still tell me that they are not even sure if they are pregnant or not! But somehow the vitamin d is to blame for their late period?!

I've erased most of those because they mean nothing if you are one or two days late once or twice or if you could be pregnant. Plus cycles are not static, and even being on a woman's retreat can change someone's cycle up to 3 or 4 days as all the woman's hormonal cycles become more synchronized to each other.

Then to go back to the first point that I made about little to no known relationship between vitamin d and estrogen. HOWEVER, there is a HUGE known relationship between magnesium deficiency and adrenal gland fatigue- and it's a KNOWN fact that vitamin D, in particular prescription vitamin d, WILL decrease magnesium levels in those with borderline magnesium deficiency- which is over 75% of the entire western world according to magnesium experts.

The next part of the equation is that magnesium decreases adrenal function (in a vicious cycle whereby stress uses up more magnesium thus putting more stress on the adrenal glands, thus requiring more magnesium, which creates the worsening sensation of stress, which depletes the adrenals further and uses up even more magnesium).

Poor adrenal function WILL cause menstrual irregularities...

In addition, you absolutely MUST have sufficient vitamin K and Vitamin A in order to prevent side effects of vitamin d, and there is a VERY high relationship between vitamin k and bleeding.


Soooo, you have women win whom I GUARANTEE are already magnesium, vitamin a and vitamin K deficient who end up taking high doses of (most of the time) prescription vitamin d and then panic because their period changes and they think it's the vitamin d.

by: Kerri Knox, RN- The Immune Queen!

In the vast majority of cases (over 90% would be my educated guess), it is NOT the vitamin D, it is the underlying deficiencies and chronic stress leading to adrenal gland fatigue all of which are brought out when they take vitamin d.

So, my 'resistance' to this- as you put it- is NOT disbelief that you are experiencing what you are experiencing, but that I absolutely know that if 95% of these women complaining of late or early periods would take: OVER THE COUNTER D3, HIGH DOSE magnesium, adequate vitamins A and K and fix their adrenal glands- then they would have NO PROBLEM taking vitamin d.

You are looking at the wrong end of the problem. Taking vitamin d and having a serious change in your period is a symptom that there is a LOT wrong with your body, and if you saw me for 2 or 3 consults, I would be able to have you fix these underlying nutrient deficiencies and other imbalances... but no matter WHAT I've said, people simply want to believe that it's the vitamin d.

Well, believe what you wish.... but I can tell you that it's hogwash that the vitamin d is causing the problem, it's only illuminating some serious underlying health issues that need to be resolved that are leaving you open for heart disease, cancer, autoimmune disease, osteoporosis and infertility.

Kerri Knox, RN

Please listen becomes....Thank you
by: Anonymous

Thank you for explaining your point of view much more clearly. I now understand why you have been stating what you have and why. I do have many health problems and am having them looked at generally, vit D being one in the mix and don't worry I am going back to the doctor who prescribed the vitamin D to discuss this issue and what it could mean.

I will be asking what other levels need to be checked. But I have had to struggle for many years against health professionals who had one stance and would not listen or explain their reasoning on many different fronts so wanted to know why you are so adamant. Particularly as I know there is a correlation of some sort in my life, though I recognize it most likely involves other factors as well, I needed to ask and to see your reasoning.

This is a big issue in my life, my menstrual cycle changing can affect my ability to see people or leave the house at times, so it's not simply a matter of putting up with it because the vitamin D will be worth it. Thanks again for your explanations they have helped me understand more and will help me as I go talk to my doctors to see what I need to do next. Your website is very helpful. Thanks for you work, and I hope I wasn't rude.

Thanks for listening.

good luck
by: Kerri Knox, RN- The Immune Queen!

Good luck.

Unfortunately, talking to your doctor about magnesium deficiency, vitamin d cofactors and adrenal fatigue will do little. Doctors do not recognize ANY of these problems and will probably laugh at you if you ask them if you should be on magnesium, vitamin a and vitamin k with your vitamin d. And unless your adrenal glands are so shut down as for you to have Addison's or Cushing's, they will not acknowledge even the slightest possibility of adrenal gland dysfunction.

This is part of the problem why these issues with vitamin d (and health in general) keep coming up- because doctors not only know little about them, but they refuse to acknowledge that they exist.

We're lucky to be having doctors finally at least recognizing vitamin d deficiency and correcting it- it's a step in the right direction.

I hope that you get what you need to be well...

Kerri Knox, RN

Vit D3 Has Helped my Cycle!
by: Anonymous

I have had extremely long cycles for about a year now. Generally around day 35 I start spotting very lightly for a full week...and between day 42-45 I get my period. This has been extremely frustrating because I've been trying to get pregnant. I can't get a straight answer from my doctor where my "day 1 " of my cycle is and it appears as though I'm not ovulating regularly either. I did a lot of reading about Vitamin D and decided to start taking it daily. I have been taking 2000-3000IU daily for the past month. This month I got my period on "Day 30"!! I couldn't believe it. I am guessing it must be due to the Vit. D because I haven't changed anything else. I'm crossing my fingers that this will help with my fertility.

prolonged period
by: Nicole

I am Sooooo glad I found this site!!!! I have an Implanon implant for birth control. I have had it for over a year and I have not had a period since I had it put in. Anyway I had blood work done and found out my levels were REALLY low, so I was prescribed D3 50,000 twice a week for three months! Two days after I took my first pill, I had a period that lasted four whole days! I have had a 2 to 3 day period since I was 15 and I'm 29! So YES without a doubt Vit D does have an affect and thats the reason why I googled it, and Lo and behold proof is on this site. I just HAD to write a comment. Thanks ladies for sharing your experiences, because I knew I wasn't losing my mind.

On Birth Control and a week late...
by: Michelle

I am also very happy to have found this site. I am 33, have 2 kids, and have been on birth control for at least 4 years now. I was diagnosed vitamin D defiecient and prescribed 50000 u/i pills once a week for 3 or 4 months. I was surprised at the cost and did some research online. After 2 months of the prescribed pills I purchased OTC D3 pills (5000u/i and 2000u/i) so I could take 7000u/i daily and come close to the originally prescribed 50000u/i weekly. My period is currently 10 days late and I was freaking out that I may be pregnant. 1 home test so far was negative. My husband suggested maybe it was due to the vitamins and I thought he was out of his mind. But I have never, ever missed a period while on the pill. I even stopped the pill after missing my period to make sure that wouldn't prevent me from getting it before the next cycle and still waiting. Planning on taking another test tonight... but I won't be as stressed now just seeing that my Vitamin D3 regimen is quite possibly the cause.

I agree
by: Angela

I actually agree with Kerri. No one really seems to be listening to what she is saying. You can say oh I only changed this, for instance taking vitamin d, however, taking one thing will change the other aspects of your vitamin and minerals. You need to maintain a well balanced diet of real foods and if you are deficient in one you may need to supplement with quality forms of it.

However, it is true some vitamins and/or minerals will cause other vitamins and/or minerals to deplete. I don't think a lot of the people posting on here are getting that. So yes you could be late because you have started a vitamin d regimen, but the studies don't show direct link to vitamin d, but possibly to the effects of vitamin d on other vitamins and minerals withinv your body. I don't believe all doctors even understand this...

That is why there are specialists. No one knows everything I don't care who you think you are, therefore see a specialist, a nutritionist or someone who knows about all vitamins and there effect when you are diagnosed with low vitamin d or whatever, don't just agree with the synthetics drugs. Too many people are dependent on chemical modern medicine. The world 5000 years ago plus didn't have that there are ways to do it naturally. But yes there are some medicines that doctors use that really are a wonder drug for lack of better words. I personally have no training in any of this it is my opinion based on research in various vitamins, nutrition etc, but you can't believe all the blogs you read if you are only reading one or two that don't have real qualifications. So research wisely, ask questions and look to the specialists and your primary doctor. The Internet is a blessing and a danger! Good luck to all, and Kerri keep up on spreading the word that it's not just vitamin d they are affecting!

vitamin d and calcium
by: Anonymous

I heard that you take vitamin d and calcium it will help slow your bleeding when you are on your monthly is this true?

by: Kerri Knox, RN- The Immune Queen!

No, Vitamin D and Calcium will not slow your menstrual bleeding. Don't know where you heard that, but there is no evidence of that.

Kerri Knox, RN

Vitamin D effected my period. Period.
by: Caryn (Texas)

I too was very grateful for this info(found Sept 2012). I am 52 and am also very regular. I had a complete blood work done in May and found all my hormones and other blood work in the normal range with Magnesium on the low end (1.7 on a reference range of 1.6-2.6) and D just barely under normal (31 on a reference range of 32-100). So the doctor recommended a "one size fits all" 50,000 i.u. Weekly... I actually, thankfully, misunderstood him to say take it once a month. So May 25 I took it, again in June and June 29th I had my last period. When my next period should have happened I also had for the first time a terrible bladder infection.

I am wondering if that too is related because I haven't had a bladder infection since my pregnancy over 15 years ago. So I went to several doctors for help with my bladder infection and they finally sent me to my Gyn( last week). He said I was probably in the first stage of menopause and wanted me to go on hormone replacement. My older sister hasn't gone through menopause and my Mom was 56.) Ugh. Why is it always just another medicinal intervention. Thankfully that is when I found this info. I added just magnesium 2 times a day to get my magnesium up and voila 5 days later my period started. I've never been so releived about my period. So I committed to telling the rest of the story here for those of you experiencing the same thing. I think a lot of our problems are "self induced". (or in this case "doctor induced". Thank you Kerry for listening!! The body is truly amazing and we do best when we listen to it. Grateful in Texas!!

more fluctuations
by: Lisa T.

Hi folks,

Nov. 30, 2012. I, too, have on-the-dot regularity in terms of my cycle. It has started two weeks early and promises to be heavy. The only change in that I've been taking vitamin D for a little over a week. I have not been taking the suggested supplements. I'll try adding them in and see if it brings me back into a normal pattern.



55 no Period in 10 years and having cramps:(
by: Anonymous

Hey Kerri,

My Dr. perscribed 50,000 units of D3-1x a week. I'm on my 3rd week of the D3 and I'm experiencing the feeling of menstrual cramps and I haven't had a period in over 10 years. This started within 5 hours of the 3rd dosage.
My Potassium level is high and I have an enlarged liver along with bone loss. The first week of D3 I went back to the Dr. and told him how badly I felt. He didn't think it was the D3. The 2nd week I also felt slugged for a few days after taking the D3.
I find this all very strange.


Magnesium Deficiency
by: Kerri Knox, Registered Nurse

I've already discussed the reason for cramps, headaches, constipation, etc. when taking vitamin d. Please see my page on Magnesium and Vitamin d. These cramps do not have ANYTHING to do with your menstrual cycle (since you are not having menses any longer), you are just having cramps from magnesium deficiency. Completely predictable and common. So common that I've written a whole page on magnesium deficiency symptoms when taking vitamin d AND a whole page on magnesium being the Cause of Muscle Cramps.

Kerri Knox, Registerd Nurse

Vitamin D and no period
by: Anonymous

April 2013. Just came upon this site and am so happy to read about others with the same situation. I am on my third week of being on Vitamin D and am over 2 weeks late for my period. I have taken 3 different types of pregnancy test all in the morning on different days in different weeks and they have all come back as negative. I have no pregnancy symptoms. The only thing different health wise in my life is taking the 50,000 unit vitamin D.

Has happened to me twice
by: Anonymous

My cycle has been noticeably different two times I have supplemented with Vitamin D. The first time was a prescription 50,000 IU 1X a week. That month I was very late - and of course concerned about pregnancy. When I went off the prescription (D2) my cycle went back to normal. No other changes.

And recently again (about 2 years later) I started supplementing with 1000IU of D3 a day and magnesium (I was recently tested and not deficient, but work inside all day so wanted to get on a good regimen. I've been doing this for a about 4 weeks and as of today I am 6 days late and of course freaking out a bit as my family is complete (2 kids already). I know I'm not pregnant and the supplements are the only changes in my diet/lifestyle.

Who knows - maybe its the vitamin D, maybe it's something else. But, the only times in my life I've been late like this I was either pregnant or taking Vitamin D (again, I know I'm not pregnant - haven't done "anything" to get pregnant in the past two months!!).

I'll be the odd duck!
by: Anonymous

I ended up in the ER last month due to severe menstrual cramps, vomiting, diarrhea, dehydration. ER personnel wouldn't deal with the gyn end of things they just got me stablized and sent me home. This has been happening my ENTIRE life. I am 53. All of my other same-age female friends are already in menopause. They laugh at me that I even still GET a period, let alone that I still get them so severely. I have no children.

While waiting for the results of an ultrasound, my primary physician did some other tests and told me I am VIt D deficient and take D3-1000 daily. I started taking it about 2 weeks ago (only 2 weeks ago). My period has always been "like clockwork" every 23 - 38 days, never, ever longer than that. Today is day 32 and I have not had a period. I am THRILLED. I hope that I never get a period again, and I hope it is due to taking the Vitamin D. Someone suggested to me that this was the only change I made in the last month so I started hunting around online and found this site. Interesting! Thanks for listening.

Extreme Menstural pains...
by: Anonymous

I just underwent a few different cancer screenings because of family history and recent complaints to my doctor. I'm 32 have 4 kids and a tubal ligation. I have been anemic for as long as I can remember and whenever not pregnant normally experience extreme pain when its that time of the month plus pmdd for about 2 weeks. 1 week before I actually start and then a full week of my period. My doctor recommended to take a "birth control" to help with the heavy bleeding and the pains I experience during that time of the month. I typically only introduce one thing at a time to my body for if something happens ill know what is the problem.

I started my period on Tuesday no sever cramping or sharp pains, and no heavy blood loss. I took my first of 8 50,000units of Vitamin D on Thursday. Still no pain...Saturday I thought my period had stopped, but it didn't and if it had that would of been a few days early which would of been odd. Anyways I was wondering if the vitamin D could have something to do with the ease of this period. And if so then I don't think I would still need a "birth control" to help with the pain. May 5, 2013

Vitamin D and late/heavy period???????
by: Anonymous

I would just like to add to this. I am 34 and my periods have always been regular and on time. I started taking 4,000 units of liquid vitamin d3 1 week before my period and it seems to have caused it to be a few days late and it was super heavy and then it stopped and started up again and it didn't officially stop until I stopped taking the supplement. Freaked out, I stopped taking it for the next week and now started back up again the last few days but now am getting cramping like Im going to start my period again. Weird!! I think Im done with the supplements and am going to just stick with the sun for 15 minutes a day during the summer. So I will read all these posts a little further since Im thinking magnesium deficiency according to what is being said.

Change in cycle
by: CDGroenig

Ever since my body stablized to the taking of prescription meds for my moods, anxiety & ADHD I have been having issues with being tired. I'm 40 and mother of 4 kids. I finally asked my doctor to do a blood test and it came back that I had a Vit D deficiency and she told me I need to take 1000mg of it. I did my own looking around and finally found a tablet I could take, as capsules have soybean oil in them, and I am allergic to soybean.
I have been taking 800 UI of D3 daily, along with a Multivitamin. I'm still tired. But my cycle has changed. Granted, it's barely been a month, but the fact that my regular 26-28 day cycle has now extended -at day 33 now- and I have a very low chance of being pregnant due to my tubes being sliced in three areas on each side. I have been having pre-signs of starting - mood swings, mild cramping, falling asleep -which is at it's strongest on the DAY I start- vaginal odor change, vaginal skin sensitivity increasing, severe headaches and a few other minor notices to my cycle starting - but I have not started.
I had thought about taking magnesium, but considering the other meds I take, I have to take it in the middle of the day so it's not messing with my other meds. I guess I'll see where things go.
And as far as this change in menstral cycle being a rarity - It's hard to say. An early post was dated 2011, the one prior to this dated May 2013. It's June 10, 2013. How many women were able to search, how many even thought to search and how many actually found this site - but did not comment? I guess we'll never know, huh?
BTW, I will be bookmarking this site so I can come back later for reading and possibly an update to things.

No periods for a year since high dose vitd
by: Cushings Patient

just adding my hat into the ring on this matter I took vast amounts of vitamin d3 in 2009 when I was seriously ill and unknown to me at the time it rebooted my adrenals and I've since been diagnosed with cushings and kidney failure and a cortisol of nearly 700...

Suspecting I was magnesium deficient due to the lack of periods and magnesium raising progesterone I started to supplement recently and slowly I will sort this and the oestrogen dominant tumour at the heart of my health issues all without surgery fingers crossed.

So what you were saying about vitd3 highlighting adrenal/cushings is spot on. I also take iodine all my other vitamin levels are high as I've been supplementing thinking it was a Bvit deficiency as Bvitamin acts like progesterone so people know.

Cushings btw is extremely common my reading shows me but a lot of people don't get diagnosed so an unexplained weight gain should be a flag for any woman to take a quality higher dose multivitamin and mineral and bump up your good fats because that helps your body make hormones and low fat on it's own can cause tumours.

Hope this helps someone.


First 25 day cycle ever...
by: Amber

My cycles have ALWAYS been about 29 days. Just had a 25 day cycle and got my period early after starting 5,000 IU D3 day. Thought I was taking plenty of mag, but guess I need to increase! Just adding to the D3/cycle experience...27 year old...Amber

Dec 2013
by: Anonymous

I am so happy to have found this site.....I am 24 haven't had sex in ober a year due to medical reasons.....recently I was diagnosed with low vitamin d difinency and doctor ia now giving me injections ever two months and am alse on 1000 units per day of D3. I was due my periods last monday (9 days) ago and srill no sign. I know I am not pregnant so I am thinking now after reading this it is the vitamin d......but when should I ezpwct them??????

vitamin d is affecting my period
by: katie

I started Vitamin d in Nov 2013 my cycle was 23 days.I am 550 my cycle has been every 16 days for the past 3 months . I have started magnesium to see if this helps. I have been taking 6000 iu . I plan to reduce my d3 to 4000 iu. Also does anyone know if d3 affects the thyroid? I am on desicated thyroid medication .

could vit d, 50,000 IU/ week change my normal cycle??
by: michelle

Thanking goodness for this site. I am 43 1/2 with one grown daughter and 4 young boys. I have been on 50,000 IU/ week since the end of my last period. I have been taking them once a week for a month, as i was at a level of 17, at the time of my check-up. I am waiting, not patiently, for my period to get here as it is the only regular and normal thing i have in my life, right now! It was, to the day, on time. I will certainly wait it out, but would like to know how much of D3 to take along with magnesium and vit k daily. I am hoping to get this back on track A.S.A.P!!!

D3 shortens menstrual cycle
by: Anonymous

I am a 40 year old, took D3 this month, my cycle shortened from 27 to 23 days. Maybe there is no literature on it, but there should be, women are not taken seriously by the medical research profession as the tests are done mostly on men. All these women on the forum cannot be wrong. So far it is just brown blood not red, the cramps are not bad, and the only thing I added to my vitamins was D3, 2000 IU. Glad I found this site, so the next freaked out woman with a short cycle due to D3 can find this information.

In the same boat
by: Youj13

I know the original posting is from forever ago however still very happy I found it!! I took 50000 d3 the day before I was to start and I am almost a week late! I have never been this late! I have surgery coming up go I have been totally freaking out! Taken 2 at hpt and negative!! I can honestly say that's the first time I've ever been happy about negatives lol I'm suppose to be on this for 8 weeks! But I hope this doesn't keep happening!

Late period vitd3
by: Anonymous

I have had a late period by a week when taking d3 also I was freaking out! I stopped taking and it became regular again. I spoke to a holistic dr who deals with fertility etc general info, she told me that when taking anything new like female vitamins d3 etc fish oils could cause an irregular cycle, everyone is different.

She also said that could be a good thing general rule of thumb that it means it working everything out and it's a good sign for the most part. We usually are lacking something in our diet being its hard these days to get from food alone being the soil is lacking minerals vitamins and all the hormones in food. Eat organic important! And take vitamins. It sucks cause I started to take d3 and other vit and I'm late again but not so stressed about this time:)

Of course too much vitamin D3 changes your cycle
by: Eva

Last year, my doctor told me to start taking vitamin D3 supplements because my levels were low on a blood test. Thank goodness I am healthy. I had no problems at all, not low on energy, no hair loss, nothing. My cycle had always been regular, and I have not had PMS my adult life (a teeny water retention, but that's it). I have always exercised regularly, even through my pregnancies, so maybe that's why I always felt great. Anyway, I started taking 4000 iu daily of D3. My period did not come and was two weeks late. I had my doctor do a hormone test and my female hormones came back normal, and my D3 was still showing low, but not as low as before, according to the blood-test. I simply stopped the D3 pill (skipped one day and went to 1000 iu the next day) and within two days my period had returned. Now, I have been taking 2000 iu (1000 in daily multi-vitamin and 1000 as a separate pill). According to a recent (annual) blood test, my D3 levels are now in normal range. Yeah, right. My period did not come this month. It is now four days overdue. I am not pregnant. Gee, I wonder what it could be. Besides magnesium, vitamin D3 also has an affect on calcium. Too much D3 leads to too little calcium, which leads to a loss of menstrual cycle. I am going to do the same thing now, cut back on the D3. I am Asian, and all my friends told me that their doctors have told them they have low D3 and told them to take supplements. We wonder if the so-called normal ranges are only based on results of white women (or maybe even just men). Maybe, I don't need as much D3 to do its job. Or could it be that since FDA does not regulate supplements, you don't know what you're getting. A 60-Minutes (or was it Dateline?) study looked at all kinds of vitamin brands. Within a single bottle of vitamin pills, if the bottle says 50mg., one pill may be 25mg, and another one may be 150mg. I don't know what the issue is. I suspect it is a combination of both: The 'normal' range may not be normal for everyone, and you don't really know the dosage of vitamin you are getting. Anyway, I am going to go down to 1000iu (from 2000 iu) for a day, then skip D3 for the following day, and I suspect my period will start. Besides, I'm actually feeling a bit crampy in my lower abdomen. The only other time in my adult life that I have felt that way prior to my scheduled period is when last year when my period stopped because of the excess vitamin D3 (but I felt crampy for two weeks). I will keep you posted, either way.

Plenty of studies on non-whites
by: Kerri Knox, RN

Hi Eva,

There have been plenty of studies done on non-whites and vitamin D. And if your vitamin D levels are coming up because of the vitamin d, then your supplements contain vitamin d.

And calcium levels in the blood do not change from taking vitamin d unless you become toxic. You took a blood test and are not toxic. So, that is not the problem. By definition, you are not toxic, nor are you taking 'too much'. You cannot BE taking 'too much' if your levels are low or normal.

You already gave the clue as to why you are experiencing menstrual issues. It's the same answer that I've given in this thread several times already. It's because you are magnesium deficient. That is why you are 'crampy' when you take the vitamin D!

Magnesium deficiency is epidemic, and you require magnesium for proper adrenal and other hormonal function. If you are getting cramps from such a tiny amount of vitamin D, just like all of the other women here, you too are almost certainly severely magnesium deficient.

Kerri Knox RN Immune Health Queen

Kerri Knox, RN- The Immune System Queen
Functional Medicine Practitioner
Immune System
Side Effects

PS: If you appreciate the free help that I give on my site, please consider making your next supplement purchase through my Health Store in order to help keep this site in operation.

by: Anonymous

Thank you ladies for your comments. I was freaking out, but now have peace. I started my dose of women once-a-day 3 weeks ago. I mormally have a regular cycle of 28 days, but now it is day 32 and nothing, only a little spotting. I was scared of having a positive pregnancy test.

Two Cycles Viramin D3
by: Habs

Was taking Vitamin d3 5000iu/day for last two weeks. Period came a couple days early - no big deal and lasted 3 days. Was lighter flow than normal. 10 days later I am bleeding again. Not sure what to say.

D3 and cramps
by: Anonymous

Okay I am trying this a 2nd time! All of a sudden this page jumped and my post disappeared LOL. Okay I am 53 and I have been using magnesium for several years, in the spray on skin type. A couple of months ago I began using vitamin D3 5000 i.u. with K2. I have not had a period in about 5 months then suddenly after a couple weeks using the D3 with K2 I started having bad cramps like I am starting to have a period! Then I started spotting and this went on for a couple of weeks then went into a full blown heavy period!!

This went on and on and I didn't think I was ever going to stop! So after 2 more weeks of heavy bleeding I stopped taking the D3 and I have used progesterone cream years ago and so started using it again and the day I started on the progesterone cream was the first day my period finally stopped.

So after about 2 weeks now I thought I would go back and start using the D3 again and within a short time I was cramping and spotting again!!!!! There has to be something about the D3... and NO I am not deficient in magnesium since I daily use the spray for several years so that is not the issue. I went without incident for 2 weeks, start the d3 again and instantly the cramps and spotting were back. So I searched/googled can d3 cause cramping and heavy period?? And found this site. although mine seems to be opposite of some people I really believe it IS the d3.

I am stopping the D3 to see if I can get my cycle back on track. Studies need to be done!! Not just for a short time but follow women for a year and see just how many have issues. I thought I was heading to menopause since I'd been 5 months without a period and I have never had one like this last one. Mine have always been regular except the 2 times I was pregnant!! I kept seeing magnesium might be the problem but as you can see I should not be deficient in magnesium and I also take folate, all the b vitamins, iron, and a multi vitamin with c and others. The only one to cause me issues, and I double checked this by using it again after I was back to normal, is the D3!

So I am not using the D3 anymore. I hate these cramps they are worse than any I ever had my entire life. These cramps are non stopping and I have compared it to child birth pain like my uterus is in a spasm non stop!! Sun for me from now on for vitamin D!

Vitamin D and late period
by: Anonymous

I have to chime in here. I was recently diagnosed with Vitamin D deficiency and was put on 3000 mg of D3 per day. After my period was several days late (I am every 28 days like clockwork), I made an appt. with my Dr. but in the meantime looked online. Sure enough, there are a tons of people with the same question - does beginning to take Vitamin D affect a normal period. I'm thinking we're on to something here. No, I'm not pregnant, and ended up getting my period 11 days late. Hoping next month will be back to normal.

Nothing's ever absolute...
by: Andrea'

In early 2012 I was diagnosed with a dangerously low vitamin D deficiency and was immediately placed on a 50,000 iu per week regimen. Accompanying this was the suggestion to see a therapist about depression. Soon thereafter I visited a naturalist who told me that a therapist wasn't necessary...just the vitamin D. And sure enough my mood swings were gone and as long as I am on my vitamin D I show no signs of fatigue or depression.

Unfortunately I never monitored any changes in my cycle. If they were shorter or lighter or late I was happy because menstruation had always been so very awful for me. Then in summer of 2013 I skipped 2 months. Now this was alarming as I knew I wasn't pregnant. My ob-gyn just brushed it off as pre-menopausal signs. My heart screeched to a halt because I've always wanted 2 more kids. Now it is December6, 2015, and my body skips periods every few months...and I am still too dumb to make the correlation until my best friend points it out 2 days ago.

I suggested a few months ago that she take vitamin D because she was feeling really low. After the first month she was alarmed at how it affected her period. I showed her my calendar and how sporadic and unpredictable my cycles have been the last 3 years. Then I began count all began after the vitamin D! I now must find another way to intake the proper amounts of vitamin D to keep me happy and energetic but I also must figure out how to get my hormone level back to where I can bear at least one more child.

Ladies be careful...not all research is absolute. All of our bodies function differently no matter what anyone says. You know your body better than anyone ever will. Listen to your body, second guess everthing, don't give up. Take care of you.

Me too!!
by: Anonymous

I can't tell everyone how relieved I am to find this site. My doctor prescribed 50,000IU of vitamin D because with a blood test I was an 8 when you should be between 50-100. At this moment I am approximately 10 days late. I took 2 pregnancy tests and both were negative. I also experienced cramping for around 4-5 days after the third dose and the week my cycle was due to start.

Glad to read all the post-thanks for sharing
by: Susan

I started vitamin D 50,000 units 4wks ago, my period late late for 5 days. You can say they is no evidence to back relation btw vitamin D and missed period but it can start here? All this people cannot be relating to same issue coincidently. And my pregnancy is negative by the way. Thank you.

Susan RN

2weeks early after taking V D3
by: Anonymous

thankfully I found this website. a few months ago I took magnesium and the next day I had bleeding but very light and I thought that's unusual so I stop the Magnesium and the bleeding had stopped as well.

My period is regular 28 days cycle and last for 4days and I'm 35 with 2kids, never take supplement before. Recently my blood test show that my Vit D is low so I took the D3 1000IU then 2days later my period comes back only after 2wks and this is the 5th day and I'm still bleeding and the 1st day was heavier than usual.

I thought it must be the D3. After reading the comments in this website I felt relieve that's nothing wrong with me must be the D3 that cause the bleeding to come early. Now a bit nervous whether I should continue with it.

bleeding after taking vitamin d pill
by: Anonymous

Hi i took a blood test last week and my doctor told me i was low on vitaman d and prescribed me 50000 units of vitamin d. I have not had a period since i had the birth control implanon and after i took the vitamin d pill i started bleeding the next day.

Glad i found this site cause i was scare of what was going on this pill does effect your menstrual. Never bleed until i took this pill going to see my doctor tomorrow

This is the latest i've ever been in my life!
by: Amy

Finally got my period on day 62 of my cycle! My cycles are usually around 30-33 days in length. This is the latest I’ve ever been in my life! I started taking a vitamin D supplement in January, (I’m writing in 2016) as I usually do in the winter. I live in Northern Canada and the daylight hours are very minimum in winter and it’s too cold to expose bare skin outside. Over the years of doing this I have noticed when I take a vitamin D supplement my periods are about a week later than usual, and that’s what happened. Then in April, instead of stopping the Vitamin D supplements like I have in past years, I switched to Cod Liver Oil. I thought this would be ok to take because the dosage of vitamin D in the cod liver oil was smaller than my vitamin D supplements and the oil has other things in it like vitamin A and omega 3’s, so I figured it was a more well-rounded, lighter supplement to take.

By the end of May I started to wonder why I hadn’t got my period yet. At this time I was on Day 48 of my cycle. I thought that perhaps Vitamin D was the connection, as I’ve noticed it making me a little bit late before, and because the only thing I had been doing differently was taking the Cod Liver Oil and getting a lot of sun as I’ve been spending a lot of time in my garden, and we’ve had unusually hot and sunny weather for this time of year. Going on this hunch, I found this website. After reading about other women’s experiences I stopped taking the Cod Liver Oil. I didn’t comment strait away because I wanted to make sure I wasn’t pregnant first.

I knew I wasn’t starting menopause yet because I’m too young, I’m 31 years old. When I stopped taking the Cod Liver Oil my cervical mucus changed, like I was ovulating. About two weeks later I finally got my period.

I read in previous comments that the problem may not be the Vitamin D itself, but rather an overly high ratio of Vitamin D to other vitamins and minerals in the body, the imbalance causing a deficiency in those other vitamins and minerals. In my case that is very probable, since I wasn’t taking any other extra minerals or vitamins, just the cod liver oil.

I might try cod liver oil again in the winter, and see what happens. I don’t plan on taking any supplements for the rest of the summer, and hopefully my body will go back to normal.

VIT D3 corelation
by: Mehreena

Hi, I'm 32 years old and 2 weeks late for my periods - not pregnant since I habe done 2 home tests. Like the other women here, I have been on the clock regular with my periods since I was 11 years old except for a few odd occasions. These past weeks I have had menstrual style cramping constantly and discharge, making me think the periods have finally started only to find that it hasn't.

Really annoying to the ppint that I have dreams of finding out I'm pregnant (not planning any more kids! ) Gew momths ago i was diagnosed with very low Vit D and put on vety high dose supplements. Yesterday it finally hit me that maybe my vitamin D supplements might have something to do with it, did a search and came upon this thread where so many others have reported similar things.

Maybe the expert is convinced there is no corelation but personally I'm relieved others have experienced this and I have a possible explanation.

Delayed period from vitamin D
by: Elizabeth P

I am also having a similar experience. I took vitamin d pills (drisdol, 50000ui) and I am now 16 days late. I feel that my whole month will skip. I've never been late, and I'm definitely not pregnant. I am sort of freaking out.


Some changes, but...
by: D.A.

June 30, 2016
I recently found my D levels to be <14 ng/ml and started on D3 10,000 IU daily. I've only been on it about a week and a half or so. My period is a little late.

However, I'm honestly not worried about it. I am more worried about my D being so low. I am older, almost 46 so it's possible mine is just from getting older, although I've not skipped a period before. And since mine is not that late, I'm not feeling like I'm skipping at this point.

However, I am really posting because the ladies here have seemed more concerned over a missed period or a period getting a little off schedule than they are of the effects of low D. Study, read, listen to the experts who have lots of lectures on YouTube, use this site.

Learn what you need to take with D for your body. I am trying to figure out the balance I need of all these nutrients too. I figure a big change might shake up my system a bit. A new diet can do the same, so why not a change like this, you know?

The only reason I'd stop taking D is if I was showing signs of hypercalcemia (or my level went too high) and even that sounds like it can be corrected with the proper balance of supplements.

So I just want to encourage the ladies out there to not panic, but take care of your D deficiency. Once we fix that, many other elements of our health should balance out. Study up! Knowledge is power!

Commenting again!
by: Elizabeth P

July 28, 2016
I commented a month or so ago, and I was about a month late. I stopped taking the pills and I was regular again. When I began taking the pills again, I was early by two weeks. Taking Vitamin D supplements definitely affected my menstrual cycle and I'm sure it affects others as well.

Don't be afraid! It's best to take the supplements and not worry about the period since it is short term.

Liz :)

by: Anonymoussue

I'm taking vitamin d as instructed by my doctor. I'm 48 and my period is 13 days late I've done 3 pregnancy tests all negative. My periods are always every 28 to 32 days. Could this be the vitamin d. Realy worried

You're 48!
by: Kerri Knox, RN, The Immune Queen

You're 48. At 48, you are bound to start having irregular periods. The average age of menopause is 51 years old and symptoms of irregular periods start up to 10 years prior. That you have not had an irregular period until now is frankly amazing.

That you believe Vitamin D is causing your irregular periods is not even a good starting hypothesis, since irregular periods at your age are not only normal, but entirely expected.

At least 5 other women who have commented were over 40, and hence their age cannot be ruled out as the prime factor in their irregular periods. Several of these women were over 50!

If you want to make good experiments, you must start with good theories and eliminate other causes of the issue. Being over 40 eliminates any possibility of starting with a good theory as you cannot eliminate the high likelihood that the issue is merely your age and the vitamin D is coincidental. And that is why I am still extremely skeptical about this relationship. Most of the women here have issues that are an OBVIOUS risk factor for already having irregular periods, and hence their observations are useless because they cannot eliminate this factor that is large possibility of the cause of their observations.

Plus I have had people write and tell me the most outlandish things about vitamin d because they confuse correlation with causation. One lady wrote me to tell me that Vitamin D definitely did something to her that makes all of the dogs in her neighborhood bark viciously at her as they had never done it before she took Vitamin D! Ugh.

Personally, I skipped my first period at the age of 45 and it was just a few days after I began taking a diatomaceous earth supplement. Was the DE the cause of my skipped period? There is no doubt that there is zero possibility of that.

I'm 45, and that is the most likely cause. But the coincidental timing made me think of this thread.

It is IMPOSSIBLE to determine if something is the cause of a problem like this when it has happened once. You took Vitamin D, your period was late. That is a 'temporal association', not a determination of cause and effect. In order to determine cause and effect, this needs to be repeated and to have all other possibilities 'ruled out' as potential causes.

In the case of a missed or early period, since the cycle is approximately 28 days, this will need to be repeated several months later, and at least a couple of times, repeated at a different time in the cycle, and have all other causes eliminated.

I've already given SEVERAL causes... legitimate causes that I find in my practice every day. But few are interested in finding out IF the phenomenon is even real by doing a Doing a Proper Self-Experiment (I believe one women in the thread who was not pre-menopausal said she actually did the experiment several times over a few months), and even fewer seem interested in finding the underlying cause, such as magnesium deficiency, which is rampant, and the subsequent adrenal fatigue, or the myriad other problems that might be the cause.

I always tell people, who have ANY problems with Vitamin D, that if they have these problems, it's a VIRTUAL CERTAINTY that it is because they have underlying nutritional deficiencies that the Vitamin D is provoking.

It is not the Vitamin D, per se, that is causing the issues, but your nutritional and underlying health issues causing the problems.

It always baffles me to find people who are relieved to find people who have the same problem and then end the conversation. Maybe I'm just more curious than most, but I personally tend to say, "Hmmm, wow, that happened to you to? Did you figure out what caused it?"

But I rarely see that on forums. To me, being in good company of having a problem doesn't relieve me, but motivates me to find a solution.

So, to the women here, please do not say that Vitamin D affected your period if you are older than 40. There is no possible way to know if your age is the cause. And if you otherwise believe that vitamin d TRULY is the issue, then do a proper self experiment to confirm.

And then seek to find out WHY by, for instance, taking the Vitamin D with it's cofactors like in the Vitamin D Absorption Pack for 6 months, getting a vitamin d level to see if you are in optimal range, and let us know if your menses are still irregular.

Because being Vitamin D DEFICIENT is a factor that needs to be controlled for as well, and almost everyone here admits to being deficient. So, if you are DEFICIENT in vitamin D and taking vitamin d causes menstrual irregularity, will it still do so if you are sufficient? Maybe it's BEING deficient that is causing the problem, and the vitamin d is just exacerbating this underlying problem. Wouldn't it be 'common sense' that if you are severely deficient in a nutrient, and that you might have been for years, that you might have some issues come up on regaining the balance of nutrients in your body when you've been starving your body of it for years.

For instance, if someone fasts or is starving for a long time, when they start eating normally again, they often get bloating, gas, poor digestion, stomach pains etc.

To use the same logic most of you are, it would be the FOOD causing the problems, but it was the FASTING that was the underlying cause of the problems. And the solution is just to wait and get things back in balance, since it will take some time to get digestion back to normal again.

Wouldn't you prefer to know rather than to declare this thing true because a few deficient women declared it to be true after taking a couple of pills? Find out for yourself. Be your own lab and do your own experimentation to find out if things are true for you, and why.

Me too!
by: Jen

My vitamin D generally runs low, about 22 ng.. when I start taking a higher dose of vitamin D3 I just stay on my period. I am currently taking 5000 iu a day and have been on my period for a month. I have tested it, I stop taking the D, my period stops. It definitely effects mine.

by: Anonymous

Yes vitamin D can affect your cycle, More specifically the pharmacutical type. I was given a prescription for 50,000 IU once a week and it most definityly changed my cycle. My body acted like it wanted to menstrate but didn't untill i stopped taking the prescription, Then my cycle acted like it normally did.

Same Issue
by: Melissa

Hi, I'm 32, and have had the same experience just recently. I took the 50,000 ui for two days and it was during my Pms. I track my period and am very regular at 28 days with extreme cramps but lighter flow bc I've been on Lithium for several years.

I have been late for at least a week and I am not pregnant. When vitamin D can affect women in a positive manner in lower dosages on their periods as several studies have shown it makes sense when taking that high of a dose it can affect your menstrual cycle.

Thank goodness!
by: Mamax8

Thank goodness that I came across this page! I have had low vitamin D for 5 years now, every now and then my GP gives me a high prescription dose of vitamin D, but mostly says my levels (24) do not require a prescription so just take over the counter vitamin D, so I am just left.

I too have affected cycles, sometimes up to 2 months late, which for 30 years have been regular 28 days. I also have bad joint pains and pains in my shins, forearm and rib bones, which is getting worse and it even hurts to walk somedays. I just feel desperately unwell all the time.

Never once have I been told that vitamin D would deplete the other vitamins i need and yet my health is getting worse and worse, but doctors dismiss me as under stress etc.

Thank you all so much for contributing to this page, since even though I see the sense that vitamin D is not causing my menstrual problems, I have been able to find information that I likely need to help me to get well again, due to the posts.

Vit. D supplementation CAN be harmful
by: Anonymous

I don't know anything about this site as I just found it when I Googled, but I'm shocked by how dismissive Kerri is to what everyone is posting! I also found out my Vit. D levels were low and started supplementing with D3. I became miserable. My PMS was much worse, my periods were incredibly heavy and I started soaking through a pad every 15 minutes.

My cycles, which are normally very regular, became irregular. I also started getting a lot of headaches which I have never had before. This went on for a YEAR because I never made the connection. I happened to read an article by Matt Stone and Dr. Garrett Smith on Vitamin D (you can find lots of info by Googling) and a lightbulb went off.

I stopped Vit. D and now my periods are back to normal and my headaches are completely gone. Oh and I also always take magnesium so it isn't that I needed more than that. There IS a lot of evidence out there that Vit. D supplementation can be harmful. You just have to know where to look.

sigh... please actually read the site
by: Kerri Knox, The Immune Queen


First of all, why do you believe that missing a period, or even feeling miserable is 'harmful'? It may not feel good, but not feeling well is not necessarily harmful. If you workout and your legs get sore, you might feel absolutely miserable, but it's not harmful. I can give you hundreds of other examples, and missing a period is not necessarily harmful.

Second, if you are low in vitamin d and stop because you feel some discomfort, I guarantee that it will be MORE harmful for you to be vitamin d deficient than to become sufficient. Please take a look at the vitamin d disease incident chart from Grassroots health.

Next, just because you take some magnesium already does not mean that you are not magnesium deficient... and from what you describe, it sounds like you are magnesium deficient. Please see my pages on magnesium dose and magnesium levels.

For those with deficiency, 600 mg is a STARTING dose.

Next, you could also be deficient in many other nutrients, see Vitamin D Wiki's page on Vitamin D cofactors for more information on this.

Bottom line is that if you have a negative response to vitamin D:
A) It's almost certainly not 'harmful'
B) It's extremely informative as to what other nutrient deficiencies you are likely experiencing.
C) You're probably extremely deficient and your negative reaction is because you are using up massive amounts of cofactors getting up to normal.

But if you choose to belive that you will be harmed more by taking a nutrient than becoming sufficient in it, and don't want to discover the other nutrient deficiencies you are insufficient in and resolve those as well, well, it's your long-term health at stake and you are welcome to risk your health in order to not experience any temporary discomfort.

But it's irresponsible to recommend others remain nutrient deficient because you read some scary things on the internet.

Thank God for the internet
by: SAinPA

I've had the same problem as all the other ladies here. I am 24 years old and have a regular 27-day cycle, but I am almost one week late on my period. About 4 weeks ago, I started taking vitamin D 2000U 1x/day. I know I'm not pregnant, but I'm still worried about this

Phew! Late Menses Annymous
by: Scientist

First, I am glad I found this page. It's explained and provided clues -a basis for me to test why my period is late


You probably do not realize the relief to see that someone shares a similar experience, for me it is a relief to see women who have been able to correlate their irregular menses to VitD supplementation. It is this piece of information that set the light bulb in my head! Of course, it's the supplementation that is affecting my menses, which as most have stated here, has been like clockwork for the past 27 years.

I am 38.
What I appreciate about your comments is that you have provided an added perspective that can potentially explain the irregularity in our periods. Note that I have used the word 'potentially' because until a focused study has been carried out, you can not definitely say that it is magnesium per se and not the vitamin in and of itself.

Science is a continuous process of discovery, who knows what research will turn over tomorrow? I take you advice on full accord and will use magnesium to aid the mt supplementation of VitD. Nonetheless, I believe this thread is on to something, sadly I am not in medical research else I'd have jumped on this as a proposal for future studies. being a scientist myself, I will test the hypothesis and get off my supplementation to see if it has an effect on my delayed menses (normal 25-27 day cycle, but as at day 31 no full flow instead started spotting at day 30, still waiting on full on period).

On a side note, how long should the sun exposure be to receive an optimal daily dose of vitamin D?

please read
by: Anonymous

While I agree more research needs to be done on the complex interactions between vitamins, I find you to be incredibly dismissive towards these women who are concerned that their periods have become irrgular after starting vit D therapy. I don't feel that you're qualified to advise women to continue a regimen of vitamin supplements that has caused such serious changes in their hormone status (regardless of whether vit D is "causative" or simple "correlating") the connection is not something to be ignore and not something you are authorized to help by promoting your own webpage and supplements. You stand to financialy gain from women continuing on their supplements and by adding in more. It's embarrassingly transparent the way this comes across. I know you won't post this but I will rest easy knowing you possibly read it. You should be ashamed of your conduct. Its obvious what your true intentions are. When something is strong enough to affect a previously normal menstrual cycle, it needs to be taken seriously yet you try to brush it off. I see you stand up for people damaged by quinolone drugs and I appreciate that, but until more research is done on Vit D and hormone changes, you saying nah its nothing just keep taking it is no different than a doctor dismissing a "floxed" patient bc their symptoms are simply correlated and not proven to be causative. Come on.

I don't think you understand
by: Kerri Knox, RN

I don't think you are understanding what I am saying or the difference between fluoroquinolone toxicity and a menstrual cycle supposedly changed by Vitamin D.

First, there are literally thousands of factors that effect a menstrual cycle. AT LEAST half the women who come here complaining of this have been late just a couple of days, then never come back here to say what happened, or they are over 40 already, or they are extremely thin, or it happened a single time and they never repeated the experiment to find out if it truly was the vitamin d, or they simply never came back to this thread after it happened a single time so that there is no evidence of the problem having repeated itself, and a few have even been pregnant and simply didn't know it and didn't think that they were!

The point that I'm making is:

a) There are SO many factors for a menstrual cycle that you can correlate a missed menstrual cycle to ANYTHING, and anyone over 40 who misses a cycle cannot claim that it's because of anything that they've 'done' because people start missing cycles once they are over 40.

The first time I'd missed a cycle, I had just started taking diatomaceous earth! I'm SURE that had I got online, I might have found women complaining that they, too, took diatomaceous earth and missed a cycle. But that it nonsense. I was over 40 and anemic, and that was the cause of my missed cycle. There is no way that I could have correlated the missed cycle to the diatomaceous earth since I was over 40! And the anemia only confounded it further.

Plus, people are overly stressed, working out too hard, too thin, too fat, macronutrient deficient, moved to a place with another menstruating women and her cycle changed to synch with the other woman's, and a whole host of other problems that could be contributing to this. I'm not 'dismissing' ANYTHING, just saying that there are thousands of factors for missing a period or having an extra one.

b) And as far as financially, you GREATLY overestimate how much I make from Vitamin D!!! LOL. I make the VAST majority of my money from random ads on the site that I don't even know what they say because they are tailored to the user and I do not see what each person sees.

I make more money on one consultation than I do in selling several months of Vitamin D.

It's patently absurd that I would give bad information to make the less than $100 a month that I make from Vitamin D tablets!

I'd probably make MORE money on Vitamin D by pandering to everyone and lying to them, but being SUPER nice while doing it, and having them want to work with me doing consultations. But I'm not interested in working with people who want me to pander to them. I'm far more interested in people who don't mind hearing the truth.

c) The BIG point that I make CONSTANTLY that everyone seems to miss and this is why Vitamin D is not like Fluoroquinolone toxicity is that YOU NEED VITAMIN D. You do not, in any way need fluroquinolones (unless it's a last resort to kill a life threatening infection).

Vitamin D is necessary to human life. We evolved with vitamin D. And so if someone has a 'reaction' to Vitamin D, ANY reaction, and they are deficient in that vitamin, then they still need to find a way to get vitamin d into them and stop being deficient!

Do you disagree? If you do, I don't think that you've read the research on Vitamin D. It would be UTTERLY negligent to say that it's better to allow yourself to have an up to 77% higher risk of cancer, an up to 50% higher risk of Multiple sclerosis, an up to 66% higher risk of diabetes, and on and on, than be late for a cycle for a few days or weeks!

When you say that I'm not qualified to tell women to continue taking vitamin d, you are saying that I'm only 'qualified' to keep people deficient so that they do not experience the slightest amount of emotional distress!

Plus, I'm NOT 'qualified' to do ANYTHING over the internet except give information. I'm not their doctor, nor am I giving them 'advice' on what to do! I'm not their mother or their sister that they can cry on my shoulder, I'm simply giving information that is as up to date and as accurate as possible from which people can make their own decisions.

Do you agree that such information should be VITAL for women to understand before they simply abandon vitamin D because they missed a couple of days of their period and they are frightened or confused about it?

So, the point here is that

d) Missing a cycle or getting off cycle is not life threatening. It's not an illness. It's not a PROBLEM, it's a SYMPTOM of a problem.

Missing a period is not a disease, it's not going to harm people in any way. In fact, it's the body telling you something. And IF there is any relationship to Vitamin d and menstrual cycles, it's patently NOT going to be that vitamin d is somehow causing 'harm' since missing a cycle is not harmful in any way anyway!

However, there are MANY ways that vitamin d acts on the body, one of them being that Vitamin D depletes magnesium, Vitamin A, and Vitamin K. And with a very high degree of certainty, I can say that if women are having these problems, then they are almost certainly VERY nutrient deficient, particularly in magnesium, and probably have some degree of adrenal insufficiency (also called HPA axis dysfunction).

And these deficiencies cause even MORE problems, like osteoporosis, chronic pain conditions, and many many more problems.

So, I'm not sure why you think it's utterly dismissive to point out the PROBLEM AND THE SOLUTION rather than to pat them on the head and put them at risk for dozens of diseases and chronic illnesses by saying they should stop taking vitamin D.

Don't you think it's more important to get the correct information to resolve what is almost certainly MULTIPLE Vitamin deficiencies, than to simply tell them to stop taking it, and panic along with them when there is nothing to panic about?

Also, the women that ARE child bearing age, do you think it would be ethical of me to tell them to not take vitamin d if they are deficient... and they get pregnant and have problems with the pregnancy, or the child has problems because THEY are vitamin D deficient too!

My goodness, I'm not sure where people think it's 'dismissive' or 'condescending' to give a problem and a solution. Do you HONESTLY think it's MORE ethical to leave them deficient, but be 'sympathetic' then it is to simply be straightforward and give them correct information, but be possibly be perceived as unsympathetic?

My time is limited, and when I write people (not including this email), I don't write long flowy things to make people feel good. I just get to the point. I'm sorry that some people see that as 'unsympathetic' or 'dismissive', but that is just how it seems when I give information about a problem and a solution rather than give a pat on the shoulder and say how sorry I am for them feeling frightened (which is probably a result of magnesium deficiency anyway), and also the result of answering the questions of more and more people online as quickly, but accurately as possible.

So, please, you tell me, which would you prefer:

A) Accurate information in a non-emotional way that gives you the ability to choose whether you should avoid a tiny bit of non-dangerous emotional reaction in order to decrease the risk of:

* Cancer
* Diabetes
* Multiple sclerosis
* Problems in pregnancy and childbirth
* Lifelong problems with your child

B) Sympathy

If you want sympathy, you can go to your mother, a sister, or a friend. But if you want brutally honest answers that give you the best information for which you can understand the problem and find the solution, well, that's what I do.

I assume that you are experiencing this same problem, so good luck to you if you choose to avoid a small amount of emotional discomfort in order to remain Vitamin D deficient.

Do you see how this is UTTERLY and COMPLETELY different from the problems of Fluoroquinolone toxicity?

Vitamin D sufficiency is a vital part of life, the side effects of which are almost always temporary, and almost always indicate deficiencies in OTHER vital nutrients; while the Fluoroquinolones are chemotherapeutic DNA damaging and nutrient depleting drugs, not necessary for human life, and whose side effects are often permanent and disabling.

Interestingly, almost certainly these women with these problems with Vitamin D are going to be the women who get Fluoroquinolone toxicity because they are so deficient in needed nutrients that the Fluoroquinolones deplete.

So, patting these women on the head and telling them to stay deficient in order to avoid some emotional distress probably would earn me more money by making them the next victims of Fluoroquinolone toxicity!

I'm just speculating based on what you have said, but I assume that you, also, have had problems with taking vitamin D? And it sounds like you might have had Fluoroquinolone toxicity? If so, this is probably not a coincidence. It's widespread nutrient deficiencies.

I hope that my assumption was incorrect and that you've had neither problem, but if you have, I wish you a speedy and problem-free recovery.

Difficult N=1 experiment scientist
by: Kerri Knox, RN

Hi Scientist,

Just be aware, again, this is a difficult n=1 for many of the reasons I mentioned, plus, being 38 you are right at the age where you might get the first signs of menopause (mean age of menopause is 50 and first signs start 10 years prior). Plus all of the other factors that could affect a cycle including stress, a daughter starting her first cycles, a daughter or another menstruating family member moving in, moving out, or even staying for the summer, more or less sex than usual, etc.

It's very hard to account for all of these variables, and cycle changes often take place over long periods of time.

While it's alluring to make causative associations, I'd recommend repeating the experiment several times at different times in your cycle over something like a 6 month time period to even consider if the results are valid.

Vit d lengthens my cycles
by: Anonymous

Me too. It's not hogwash. I did take whole food d with cofactors 5000mg per day and my cycle was late for the first time in my life. I'm not sexually active so no chance of pregnancy. Vitamin d was the only change. Also magnesium shortened my cycle and it normalized when I stopped it. Magnesium increases estrogen though and that's studied and proven in double bl8nd placebo tests, as I learned from gynecologist Dr Sarah gottfried, so that wasn't a surprise. The vit d increasingy cycle was a surprise. Also stop trying to invalidate people for being anxious over late cycles. Just because it doesn't bother you doesn't mean there is something wrong with the fact that it stresses most women out.

My Experience
by: Aine

Hi I have found this thread invaluable.

This is my story:

In Dec 2016 I was advised by doctor to take 800IU a day of vitamin D. I had up until then very regular periods 27/28 days. Then oddly my periods changed I had a 38 day period the following month and nearly went mad due to the PMS lasting nearly 2 weeks. Then things went back to normal the following months. I had only taken the vitamin D tablets for 3 weeks.

Then this year following a routine blood test (Jan 2018) I was advised to take 4000IU (four thousand)per day. Then having had a normal period since Feb 2017 I completely missed one! I subsequently stopped taking the vitamin D supplement after 3 weeks (I only had a month supply) and my periods have returned to normal.

The disturbed periods both occurred while taking Vitamin D. The higher the dose the worse the effect was on my periods.

This might be a coincidence by I definitely think something was off (maybe the vitamin D effected my magnesium levels which in turn upset my hormones?

Regardless it's food for thought.

I hope my story is of some benefit to others.


(41 yrs old, 2 girls aged 7.5yrs and 9yrs from Ireland).

Vitamin D3 stopped my period
by: Ann

Vitamin D3 absolutely stopped my period for three months until I determined that my supplement was the culprit. The problem for me was the capsule oil that the D3 was dissolved in. Soybean oil. Both soy and sunflower oils are phytoestrogenic. Once I stopped taking it and managed to get direct sunlight on my skin instead, my menstrual cycle returned.The hyper anxiety from estrogen dominance also dissipated. Breasts are back to normal. PHEW! I'm never going there again.

Missed one too
by: Michelle

I was asking the same questions about missing a, very on schedule period, while having just been prescribed 50,000 IUS and taking them for three weeks. When I googled the question, I was relieved enough seeing comments of similar situations, that I decided to see for myself. I stopped taking them, at that high dose and my "friend" was back, in full force, the next cycle. I asked my doctor about it and she had no answer, except to say that she was glad I was still taking a regular dose plus magnesium. Good luck!!

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