Most Americans and Canadians up to age 70 need no more than 600 international units (IUs) of vitamin D per day to maintain health, and those 71 and older may need as much as 800 IUs, says a new report from the Institute of Medicine. The amount of calcium needed ranges, based on age, from 700 to 1,300 milligrams per day, according to the report, which updates the nutritional reference values known as Dietary Reference Intakes (DRIs) for these interrelated nutrients.
The report's recommendations take into account nearly 1,000 published studies. A large amount of evidence, which formed the basis of the new intake values, confirms the roles of calcium and vitamin D in promoting skeletal growth and maintenance and the amounts needed to avoid poor bone health. The current evidence in fact seems to suggest the need for increasing Vitamin D levels not only in the elderly, but also in athletic populations. In fact, young athletes and dancers have been recently identified to present vitamin D insufficiency, despite the fact they live in a sunny country, suggesting that screening and increase Vitamin D intake is necessary to avoid health problems.
The committee that wrote the report also reviewed hundreds of studies and reports on other possible health effects of vitamin D. While these studies point to possibilities that suggest potential benefits of Vitamin D supplementation, they have yielded conflicting and mixed results. Rigorous trials that yield consistent results are vital for reaching conclusions, as past experiences have shown. Vitamin E, for example, was believed to protect against heart disease before further studies disproved it.
Adequate Vitamin D levels seem to be important in athletes (in particular female athletes) as a serum 25(OH)D concentration of >or=32 and preferably >or=40 ng.mL(-1) can reduce the risk for conditions such as stress fracture, total body inflammation, infectious illness, and impaired muscle function.
A part from supplementation, outdoor training time (during peak sunlight) is important and can influence Vitamin D levels.
Something else to think about, in particular in athletes training and competing indoor and in athletes leaving in “dark” countries.