Wednesday, December 29, 2010

Setting the Optimal Dose for Vitamin D

The Institute of Medicine (IOM) created much confusion. So I would prefer mentioning this situation as little as possible.

Determining how much Vitamin D anyone should or should not take in supplemental form is almost impossible. The IOM is, in its narrow interpretation of limiting Vitamin D (up to 600 IU per day and the maximum limit allowable 4000 IU), not keeping up with recent science. It is by now well understood that Vitamin D has receptors in virtually every part of the body. That means that Vitamin D is not just a vitamin for bone health.

Leaving that fact aside, it should be understood by any self-respecting scientist that, when it comes to vitamins and minerals, the optimum level cannot be determined by the type of controlled study the IOM seems to need in order to find the optimum level of a nutrient. The type of study could not possibly be done unless there were a standardized person at a specific weight or size or whatever.

But we all know that there are small people and large people; there are people who tend to be obese. There are people who are light-skinned who cannot tolerate the sun but can make Vitamin D very easily; those who are dark-skinned cannot make Vitamin D as easily. There are people who have absorption problems, and there are people who have kidney disease, and there are people with all kinds of genetic variations. Exposure or non-exposure to sun changes the variables enough to make a study the IOM seems to need worthless. And who says that the size and weight of that standardized person is optimal.

Granted taking large amounts of Vitamin D has its risks. But to be categorical about Vitamin D levels or any other kind of nutrient flies in the face of science.


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