Magnesium Deficiency & the Sublingual Epithelial Test

by John
(Kitty Hawk, NC)

I have been taking Mg supplements for years and have classic symptoms of low Mg. I take high quality brands from Source Naturals, Jarrow, Doctor's Best, etc., yet still have to take Magnesium from morning until night to prevent twitching in calves, anxiety, irregular heart beats, etc.

Serum Magnesium was 1.63 mEQ/L in the morning after I had already taken probably 50 - 75 % of the RDA prior to the test and had been taking Mg daily in large dosages for probably more than 10 years before the test. My PTH and calcium are normal, as are all values on the Basic Metabolic Panel. I have been to a cardiologist and EKG and ECHO tests are normal. Blood sugar is normal, HA1C = 4.7, TSH = 1.57. I exercise regularly but have learnrd to take Magnesium prior to beginning exercise (50 % of RDA) to prevent problems with irregular heartbeats.

I think that I am a candidate for the sublingual epithelial test. Does a doctor need to order it? I don't think that my primary care doctor knows about it, and it probably is unavailable through my insurance. Do you have any suggestions about how to go about getting the test? Is the sublingual epithelial test expensive?


Comments for Magnesium Deficiency & the Sublingual Epithelial Test

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Sublingual Epithelial Test is Unnecessary
by: Kerri Knox, RN- The Immune Queen!

Hi John,

I'm not sure exactly what you mean by you are a 'good candidate' for the sublingual epithelial magnesium test. Anyone would be a 'good candidate' who has symptoms, but I'm not sure what that test would tell you any more than what you already know.

Your regular magnesium level in your blood is already low (most cardiologists use a 2.0 as the lowest acceptable number). So, you have:

1) A low or borderline low serum magnesium level


2) Active symptoms of magnesium deficiency

Jigsaw Health Magnesium Is for Movement Video

The sublingual epithelial test is not going to help you. If it's normal will you decrease the amount of magnesium that you are taking? No, you already know it controls your symptoms. If it's low are you going to take even more magnesium? No because you already WOULD be taking more magnesium if you could manage to get it into you, right?

So, we need to figure out why your magnesium needs are so high and I have a couple of suggestions. First, read my page on Magnesium Absorption and make sure that all the factors required for magnesium absorption and activation are all taken care of.

Next, you may have severe Adrenal Gland Fatigue. Stress causes cortisol levels to go up and high levels of cortisol and stress 'use up' magnesium at a very high rate. If you were to get any test, I would suggest that you get an Adrenal Function Test and correct your adrenal function.

In addition, your diet may be causing you to have many problems as well, so taking a look at your diet and eliminating processed foods, sugar and 'non foods' is essential as these end up being 'negative' nutrition foods that actually use up more magnesium than they give you due to the stress that they cause and the inflammation in the digestive tract that can lead to malabsorption.

So, there is a lot that you can do to try to lessen your need for magnesium and potentially improve absorption so that eventually you may not require quite so much magnesium.

Kerri Knox RN

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

Endocrinology Appt.
by: John


Thank you for your advice. My thinking in having the sublingual epithelial test was that it would confirm what I already know, serum Mg blood tests are not that helpful. My insurance's lab uses 1.3 - 2.1 mEQ/L as the standard range. This is clearly not right. Also, I would like to know why Magnesium is not tested for with a Basic Metabolic Panel?

My nutritional status is good. I spend $250 per month on the best supplements out there, guided by 30 years of nutritional research. I am 54.
For example, I take molecularly-distilled EPA/DHA 2:1, DHEA 25 mg timed-release, resveratrol, etc.

My C-Reactive protein is <0.5 mg/DL

I currently have an appointment scheduled with an endocrinologist on 6/17/11. I suspect that I may have dyautonomia, or Mitral Valve Prolapse Syndrome. I'll keep you posted on what I find out.

Mg update
by: John

My endocrinology appt. led to blood work, and Mg disorder was not caused by digestive problems, or high cortisol, or high catecholamines. However, 24-hr urine for Mg amd Ca are very high. I have now done 2 24-hr urine teats and Mg was 517 mg/24 hr, and 411 mg/24 hr with a standard range of 28 - 180 mg/ 24 hr. I was referred to Nephrology because testing seems to indicate that my kidneys are involved, and I have been diagnosed with hypomagnesemia. Because this is somewhat unusual, I have been referred outside of my insurance network of doctors to the Nephrology Dept. at Emory Clinic in Atlanta for more advanced testing and consultation. I will update when I know more.

Maybe too much supplement?
by: Anonymous

I'm really confused my the follow up. He has very high levels of Mg according to his urine tests, and he's taking all these Mg supplements. So the kidneys are excreteing all this extra Mg. What made the man think he low levels to begin with? Seems his body just doesn't need all the supplements.

Hypo = too little
by: Frank

Hypo means too little in the blood.

Potassium link
by: Paula

I had a similar situation, taking lots of Mg but not showing optimum levels on the Red Blood Cell test for Mg which is much more appropriate that a serum test. I did hair mineral analysis and learned I did not have enough Potassium which is needed to utilize Mg. I was also low in Sodium so now take Celtic Sea salt.

Magnesium Update
by: John

After finally being seen by Duke Nephrology Dept. (Kidney Drs.), it was determined that I have a condition known as Isolated Renal Magnesium Wasting, a fairly rare disorder, but which now makes perfect sense to me. I treat my symptoms by taking several types of high-quality magnesium supplements, mostly purchased at, including a liquid ionic form of Mg, known as Mega-Mag.

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