How Much Vitamin D Do You Need?
Bone health was the single focus of the Institute of Medicine's recommendations on how much vitamin D and calcium people should get.
The recommendations for adults up to age 69 rose to 600 IU/day, and to 800 IU/day for adults starting at age 70. Older adults need more vitamin D because as they age, their skin does not produce vitamin D efficiently, they spend less time outdoors, and they tend to not get enough vitamin D.
The committee did not consider the emerging research on any other conditions. Patsy Brannon, PhD, RD, a Cornell University professor of nutritional sciences and a member of the IOM committee, spoke about that at the American Dietetic Association's 2011 annual meeting in San Diego. "The committee of 14 scientists reviewed more than 1,000 publications and determined that the evidence was inconsistent and inconclusive to include any other health benefits in the new recommendations," Brannon said. "The committee is not dismissing the role of vitamin D in other areas, we need more clinical trials, consistent evidence, and evidence that supports causality."
Best Sources of Vitamin D
The sun is an excellent source of vitamin D, but it is hard to quantify how much vitamin D you get from time in the sun and the risk of skin cancer may outweigh the benefits. Food first, says Baylor College of Medicine dietitian Keli Hawthorne. "Supplements can fill in the gaps but it is always better to try to meet your nutritional needs with foods that contain fiber, phytonutrients, and so much more," Hawthorne says.
Unless you enjoy a diet that includes fatty fish or fish liver oils, it may be hard to get enough vitamin D naturally without eating fortified foods or taking a supplement. "The major dietary source of vitamin D comes from fortified diary, along with some yogurts and cereals," Hawthorne says. Mushrooms, eggs, cheese, and beef liver contain small amounts.