Vitamin D3 vs Vitamin D2
Are You Getting the Right One?

Vitamin D3, Vitamin D2. They’re the same thing right?

Well, no. Vitamin D Absorption is very much affected by which type of Vitamin D that you are taking.

Now that you know what your Normal Vitamin D Level should be and you know what your Vitamin D requirements are, you should know what the RIGHT kinds of Vitamin d supplements are.

So, you've had your Vitamin D Levels Tested and you and your doctor have decided that you should be taking Vitamin D Supplements. Your doctor gives you a prescription, but it probably doesn’t say Vitamin D, but some other name that you don't recognize.

Most likely, this Vitamin D is NOT what you want to be taking. Most over the counter Vitamin D supplements and ALL prescription Vitamin D supplements contain Vitamin D2.

So what's the difference? Vitamin D is Vitamin D, right? And a PRESCRIPTION is going to provide a form with the best Vitamin D absorption and the best quality, right?

Unfortunately, no.

Vitamin D2 vs Vitamin D3

Vitamin D2, also called ergocalciferol; and Vitamin D 3, also called cholecalciferol.

Vitamin D2 was the first synthetic form of Vitamin D and is the form of vitamin d in all Vegan Vitamin D. It was used, and still is in many cases, to fortify foods, make some Vitamin D supplements and is the basis for ALL Prescription Vitamin D.

But it is a far inferior form of Vitamin D that does not get absorbed into the body well. This is a phenomenon called bioavailability- or in this case simply Vitamin D Absorption. Many vitamins are not necessarily bioavailable, therefore taking vitamins does not mean that you actually ABSORB the vitamin.

Vitamin D2 is one of these vitamins that is not very bioavailable, yet this is the ONLY form used in any prescription Vitamin D that you will get!!

The Vitamin D Research supports this extremely well:

“… cholecalciferol (vitamin D3) is substantially more potent than ergocalciferol (vitamin D2).” ‘Vitamin D in Health and Disease’ Heaney, RP

“Vitamin D2 should not be regarded anymore as suitable for supplementation or fortification.” From ‘Vitamin D2 or vitamin D3?’ Mistretta, VI et al

“D2 (ergocalciferol) has lower bioactivity, poorer stability, and shorter duration of action, resulting in approximately 33% lower potency compared with vitamin D3” From ‘The Value of Vitamin D3 over Vitamin D2 in Older Persons’ Barbara J. Zarowitz PharmD, FCCP, BCPS, CGP, FASCP









“Vitamin D2, or ergocalciferol, should not be regarded as a nutrient suitable for supplementation or fortification.” From ‘The case against ergocalciferol (vitamin D2) as a vitamin supplement’. Houghton LA, Vieth R.

"...Vitamin D2 is only about 20-40% as effective as cholecalciferol …” Michael F. Holick, ‘The Vitamin D Epidemic and its Health Consequences’.

Not JUST Absorption

If it were simply an issue of worse absorption, then you could simply take more to do the same job. But unfortunately, vitamin D 2 just doesn't DO the job that vitamin D is Supposed to do.

One consequence of vitamin D deficiency is that the Parathyroid Gland becomes overactive, altering calcium metabolism. When vitamin D is replenished, then parathyroid hormone is lowered back to normal levels. But in a few studies, the parathyroid hormone was NOT decreased to normal with the administration of vitamin d2, but it DID decrease to normal with the Vitamin D3!

You can see that Vitamin D Absorption and effectiveness is Very Dependent upon which type of Vitamin D you choose, and that it’s a no-brainer to choose the right form of Vitamin D supplement.

If you choose to take a Vitamin D supplement, don't bother getting a "Prescription Strength" Vitamin D supplement, just go Buy Yourself a Bottle of Vitamin D 3 instead.

Make sure that it says Vitamin D 3 or cholecalciferol.

But aren't Vitamin D 3 supplements dangerous? Can't you Overdose on Vitamin D?

There is a risk to everything that you do. So, of course there is a risk with taking Vitamin D 3 supplements.

But.... click next find out the truth.

Next --->
Overdose on Vitamin D

Vitamin D Resources

Free Vitamin D Lecture- don't miss this lecture by Dr. Mercola that busts myths about sunlight and how much vitamin d3 you REALLY need.

5000 IU Vitamin D 3 Supplements- Vitamin D3 is really the ONLY vitamin d that you should be taking. Get Vitamin D 3 in a clinically relevant dose for adults

Vitamin D in a Spray!- This Vitamin D3 is GREAT for kids. Just a spray a day is all it takes.

Vitamin D3 and Solar Power Book- Take a look at this EYE OPENING book. This fascinating account of the health benefits of Vitamin D will keep you turning pages far into the night!

Do you have a Question about Vitamin D3 vs Vitamin D2- or Any other question that I haven't answered yet? Ask it here!

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Click below to see already asked questions...

Low Vitamin D2 Level and Normal Vitamin D3   My doctor did a vitamin D level on me and my Total vitamin D 25-OH (D3) was 45 and my Vitamin 25-OH D2 level was undetectable. He said less than 30 is ...

Source of Vit D3 that's not from Lanolin 
1) I am ALLERGIC to lanolin and I understand that the 2 sources of Vit D3 are Lanolin and Fish oil. I have had 2 episodes recently that the Supplement ...

Difference between Vitamin D an Vitamin D3 
Any difference to these two types of Vitamin D?
My family doctor found out my Vitamin D level is very low; I started to take Vitamin D3 for 2000iu per ...

Blood test proof that D2 worked better than D3 for me contrary to what you say  I was tested(25 HydrxyOH) in May and found to be deficient Level 26.6 put on Vit D2 for 6 weeks(50,000 X 6) and then retested 2 mos later and my level ...

My Doctor Said Not to Use More Vitamin D3 
Which is better D3 or D2? My doctor has prescribed 50,000 iu vitamin D2 for 12 weeks. It has been 8 weeks and my levels have not increased. No my ...

doc gave my mom D2 prescription  I don't know what my mom's vitamin D levels REALLY are as this is the same doc that tested my dad inaccurately, but since doc gave her a script for 1.25 ...

You are Using the Wrong Science. Vitamin D2 is equally as effective as Vitamin D3  Read this study :


Study Says D2 is as Effective as D3










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One A Day Women's 50+ Advantage 
One A Day Women's 50+ Advantage. This vitamin pill has 800 I.U. of cholecalciferol.

What a surprise!

Photo by Jo-H











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Vitamin D3 and Vitamin D2 dosages  My Vitamin D blood level is 20 ng/ml. My doctor prescribed 50,000 iu three times a week for 16 weeks. According to what I'm reading, this is Vitamin D2....

Is My Prescription Vitamin D2 or Vitamin D3?  I have been tested and have a Total Vitamin D, 25-OH of 16 mg/ml. I am a 60yr old male, worked in doors for 30yrs and have had little sunlight. How bad ...

Vitamin D from Lanolin or from Fish  Which is better and easier to digest the one made from Fish oil or the one from Lanolin? I take them with food but have IBS which makes my stomach very ...

What Kind of Vitamin D Should I Take? 
My doctor called me with low vitamin D result of 15.8 ng/ml. She told me to take D'Active. Did you ever hear of this vitamin/supplement? Please respond ...

Why would my Doctor Prescribe Vitamin D2?  
If OTC vitamin D3 is better to restore VitD deficiency, why would my doctor prescribe 50,000 IU of Vitamin D 2 twice a week? My level is 7 ng/ml, I ...

Normal levels for 'D2' and 'D3' 
There is so much information about Vitamin D that I am somewhat confused. My blood levels were recently drawn. The MD said my "vitamin D 2" was less ...

Vitamin D3 
I recently started taking New Chapter's Bone Strength Take Care.

The three tablet's a day it indicated should be taken contain 1000 IUs of Vitamin ...

Supplement with D2 or D3? 
My rheumatologist prescribed 50,000 IU capsules to be taken 1 per week for 5 weeks, in response to my Vitamin D levels of 11 ng/ml. She prescribed ergocalciferol....

Vitamin D or specifically Vitamin D3? 
I was originally diagnosed with Multiple Sclerosis in 1994 and in 2009 was rediagnosed with Transverse Myelitis. My symptoms are Very similar to MS although ...

Over the Counter Vitamin D 
I had my yearly blood work and this is the first year for checking my vitamin D level. They told me that my level was 31 ng/ml and told me to take a ...

vitamin D3 vs. Vitamin D  Photo by Duncan


I am a 49 year old man, and my Vitamin D Blood Level is 17.8 ng/ml.

My doctor recommended that I take Vitamin D3 4000 ...

Low D2 High D3  My D2 is very low and my D3 is high. Should I be concerned?

_______________________________________

ANSWER:

Can you please give me specific numbers ...

Is Alphacalcidiol Vitamin D2 or D3 
My doctor has Prescribed for me 1mcg of alfacalcidol is it D3 or D2?

__________________________________

Hi Moutaz,

If your doctor prescribed ...

Can Vitamin D 2 be toxic?  Is D 2 toxic?

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ANSWER:

Anything can be toxic at high enough doses. Including water, sunshine and oxygen!...

Vitamin D3 and frothy urine  I started taking fairly large amounts of vitamin D3, but then I noticed quite significant frothiness in my urine. And yet, according to the internet, vitamin ...

What is the name of the Vitamin D that is compounded?  I have a very low Vitamin D level, and my physician wants to start me on prescription strength Vitamin D. Do I need to ask for a prescription for Vitamin ...

The Research Used for this
Vitamin D 3 vs Vitamin D2 Page

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Vitamin D Functions and Uses

Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans

Evidence that vitamin D 3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2

The case against ergocalciferol (vitamin D2) as a vitamin supplement

The tolerability and biochemical effects of high-dose bolus vitamin D2 and D 3 supplementation in patients with vitamin D insufficiency

A COMPARISON OF THE HYPERVITAMINOSES INDUCED BY IRRADIATED ERGOSTEROL AND FISH LIVER OIL CONCENTRATES