What is the Correct Vitamin D Dosage?


Annette posts a question to metabolism.com since she is on a high dosage of vitamin D due to intestinal surgery. Is the dosage too much for her, she wonders?

When the intestines fail to absorb fats due to surgery or due to disease, Vitamin D which is a fat soluble vitamin, can see its levels fall dramatically. Otherwise healthy people in the U.S., however, are being found to have unacceptably low Vitamin D levels. Is it due to inadequate diet or is it a result of wide spread sunlight phobia?

Here is Annette’s post followed by my response to her question. Answers to these questions are contained in this exchange.

Annette writes:

I had a Bilio Pancreatic Diversion surgery done in 1990. My Vitamin D level is low, at 15.
My Dr. has me on 50,000 iu of Vit D every other day, 4,000 iu on the other days.

May I ask you, what is your opinion on this amount of Vit. D. The 50,000 iu capsules are by prescription.

Thanks so Much,

AS
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Metabolism.com responds:

Vitamin D deficiency is a serious problem and has been largely overlooked in the general population until recently. Vitamin D is not only important for bone health but we are learning it is important for the immune system and may help protect against certain cancers. In my medical practice in Florida I am finding an alarming number of my patients with very low and borderline low levels of Vitamin D that were totally unexpected. I assume it is because everyone knows that sunlight is bad because it causes wrinkles and skin cancer. The further north you live the weaker the sunlight so the incidence of vitamin D deficiency is higher.

Until recently the recommended daily Vitamin D allowance was 400 IU but recently this was increased to 800 IU and some authorities recommend higher amounts.
10,000 IU levels daily for the average normal person is thought to be an upper limit before toxicity can be seen. Vitamin D is a fat soluble vitamin so in people who have problems absorbing fat, such in your case after intestinal bypass surgery, higher amounts are needed. Vitamin D doses of 50,000 IU at a time are not unusual but are usually given only a few times weekly or monthly, depending on needs. A handy tip is that deficient Vitamin D causes serum calcium levels to be low, so many clinicians will monitor serum calcium levels to help adjust the prescription.

Although I can’t recommend medical therapy in this forum I have some thoughts I can share. Why not get another blood vitamin D level measured to see if the amount you are getting is okay? Calcium levels go up in vitamin D excess so a serum calcium level that is elevated can be an indication of too much vitamin D.

Hope that helps. Keep us posted.

The metabolism.com website disclaimer applies to this and all my posts.

G. Pepper

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  • Robert

    Dr. G. Pepper,

    Is there a direct test available for the quantification of Vit D3 in blood/serum? Do you think clinicians would prefer D3 tests or 25(OH)D tests? What would you consider to be more valuable?

    By D3, I mean cholecalciferol.

    Regards

    Robert

  • Hank Frier

    The other issues leading to low vitamin D levels in the population are two-fold. The wearing of sun screen blocks the rays from converting vitamin D in the skin akin to those who avoid the sun. Secondly, as we age our ability to convert in the skin is decreased, hence the increasing requirements as we age.

    Hank