Vitamin D in the News Again!

On November 30, the Institute of Medicine (IOM) released new guidelines for the Recommended Daily Allowance (RDA) of Vitamin D. Since 1987, the RDA of Vitamin D has been 400 IU (International Units) for everyone from 1 to 70 years old. With this report, the RDA was raised to 600 IU.

There are a few problems with this report and how the conclusions were reached.

1. The focus is solely on bone health. Despite the wealth of valid research on vitamin D conducted over the past 15 years, the guidelines only discuss how much is needed to protect bones from rickets in children and osteomalacia in adults. While these conditions can result in deformities of the skeleton and fractures due to weakened bone, Vitamin D deficiency causes a host of health problems before the skeleton is compromised. Research has shown that a lack of adequate Vitamin D can be linked to increased risk of cancers, heart disease, problems with immunity, depression, autism, and many other chronic health problems.
2. The report states that a daily dose of 10,000 IU may be toxic. While it is unwise to take high doses of Vitamin D for long periods of time, it is much more difficult to reach toxic levels than once thought. If we allow ourselves 20-30 minutes of full sun exposure, our bodies will naturally produce 10,000 IU. No reports are offered regarding toxicity at this dose, either through sun exposure or oral supplementation.
3. Blood tests for Vitamin D are not discussed. There is a simple, reliable blood test for Vitamin D that can easily detect deficiency and potential toxicity. The reference range for this test, 25(OH)D, is 32-100 ng/mL. In other words, anything below 32 reflects deficiency, anything above 100 reflects potential toxicity. The optimal range for this test appears to be 50-80 ng/mL. I have used this test several times in my office, and most patients' results are between 30 and 40 ng/mL, well below the optimum range. Adding 5,000-10,000 IU of Vitamin D almost always improves their symptoms as their blood tests gradually improve. Dosages are changed based upon follow-up testing and increased availability of sunshine. Never have I had an incident with Vitamin D toxicity using this approach.
4. The recommendations don't make much sense. This chart shows that all age groups and demographics, with the exception of those 70+ years old have identical requirements for Vitamin D. Using this logic, it doesn't matter if you are 2 years old or 55, or if you are male or female, or you get tons of sun or none at all, or if your natural skin pigment is light or dark, or if you are pregnant or not, or if you weigh 25 pounds or 300.

If you are genuinely curious about the role of Vitamin D in health, Vitamin D Council is a great place to start. The site is loaded with research, Vitamin D resources, and discussion about the importance of Vitamin D.

If you are interested in learning about your Vitamin D status, get tested!