The Institute of Medicine’s new Vitamin D and Calcium guidelines, released late in November The IOM review committee says that most Americans do not need vitamin D supplements, that 600 IU/day is sufficient and that there’s no firm evidence that supplementation beyond that level has health benefits aside from bone health.
The committee’s positions took many nutrition-focused clinicians by surprise because it runs directly counter to a swelling tide of epidemiologic, observational and case-control evidence that vitamin D in doses as high as 1,000-5,000 IU daily, could reduce risk of heart disease and various cancers, and ameliorate depression, diabetes, MS, autism, and other common diseases.
Read the IOM report online, free of charge: http://books.nap.edu/openbook.php?record_id=13050
The intent of the IOM report was to reinforce the status quo: to state that there is not an epidemic of vitamin D deficiency and that most North Americans get enough vitamin D presently from a combination of food and supplements. At the same time, the panel acknowledged with some ambivalence that high dose vitamin D supplementation is safe. Not only did they raise the tolerable upper limit from 2,000 to 4,000 IU/day, but in the body of the report appears the statement that even 10,000 IU/day is probably safe. That is the only part of the report that can be considered a “step in the right direction”, says Leo Galland, MD, Founder Foundation for Integrated Medicine
They rejected as inconclusive and inconsistent the science indicating that vitamin D improves any aspect of health other than bone strength, or that blood levels greater than 20 ng/ml prevent any illness. And they raised concerns about the results of some studies that show an increase in mortality and cancer rates at levels of 25-OH D in the range of 40 to 100 ng/ml.
The purpose of the IOM report was to make population-based recommendations. As a physician, it is clear that there si no real “standard vitamin D dose”. Vitamin D dosing needs to be highly individualized.
For example: In women who already have breast cancer, the higher the levels of 25-D, the less the risk of distant metastases, at least up to plasma levels of 70 ng/ml. The optimal level for patients with multiple sclerosis is not known, but may be just as high. The optimal level for someone with sarcoidosis is more likely about 16 ng/ml. Cardiovascular risk decreases progressively as 25-D levels rise to about 43, and then hits a plateau. Individualization of treatment decisions is critical. Unfortunately, the IOM report sheds no light on how to make these decisions. But if read in its entirety, it does establish an official sanction for the use of high-dose supplementation, which is a worthwhile outcome!