Thumbs down on Vitamin D?

By on April 7, 2011 under Nutrition, Osteoporosis/Bone Health, Sunshine

I received many emails and phone calls asking me about the Washington Post article and the subsequent media “buzz” which was somewhat negative about Vitamin D supplementation. Here is a summary of the key points of the report:

1) US and Canadian governments asked the Institute of Medicine to review the data on Vitamin D and update the recommended daily allowance (RDA) for Vitamin D.
2) The committee increased the RDA to 600 IU for children and adults and 800 IU for those over the age of 71 (previously it was 200 IU for children, 400 IU for adults, and 600 IU for those over the age of 71).
3) The committee concluded that further research is necessary before recommending a higher RDA.
4) The committee cautioned against taking megadoses of Vitamin D. They do not recommend taking more than 4,000 IU.
5) They conclude that most people get “enough” Vitamin D from food and sunshine and that Vitamin D deficiency is not widespread.

Discussion: The media has taken these somewhat anticlimactic committee findings and turned it into headlines like “Vitamin D Supplements Get a Big Thumbs Down”. The committee is saying that there isnt’ enough evidence to recommend higher doses of Vitamin D for the general population.

We get most of our Vitamin D from sunshine so our Vitamin D levels are primarily determined by the amount of sunshine we get and the efficiency of our body at converting the sunshine to Vitamin D. It is true that we probably wouldn’t need to take Vitamin D supplements if we sit in the sun in our bathing suit without sunscreen until our skin turns pink (15-20 minutes) at least several times per week. 
 
I think the committee neglected the most important question – what is the optimal level of Vitamin D? The committee does not recommend checking Vitamin D levels as a screening tool for the general population (imagine how expensive that would be for Medicare and the insurance industry).

I agree that people should not take high doses of Vitamin D (above 2,000 IU) without checking their Vitamin D levels and under the direction of a physician. Vitamin D is fat soluble and excessive amounts can not be cleared in the urine so you can overdose on Vitamin D. Sometimes high doses are needed to boost levels in patients with severe deficiency.  I agree that well-designed research studies are needed to determine the optimal levels of Vitamin D. Based on my research, I recommend a level of 50-65.Studies have shown a decrease in prevalence of colon, breast and kidney cancer, diabetes, multiple sclerosis, and fractures when Vitamin D levels increase from 30 to 55. Studies have shown that healthy adults who get plenty of sunshine can naturally attain Vitamin D levels up to 65 in the absence of supplements.