Bone Protection: RDA for vitamin D may need to be raised, say researchers

With an aging population, and with people living longer, experts say bone fractures will become a bigger and more costly problem unless more is done to prevent them. While vitamin D has been shown to reduce the risk of fracture in the elderly, a study recently published in the Journal of the American Medical Association (JAMA) suggests that the current Recommended Dietary Allowance (RDA) for vitamin D, which is 400 to 600 IU per day for older adults, may not be sufficient to protect bones. The researchers concluded, though, that higher daily doses, in the range of 700 to 800 IU, might reduce the risk of fracture by approximately 25%.

The review analyzed the results of seven trials that all compared fracture rates among subjects 60 years of age and older given vitamin D supplements to those among similar subjects given only calcium or placebo. The researchers found that only subjects receiving higher doses of vitamin D supplementation had significantly fewer fractures than did subjects in the comparison groups.

“In the future, we may need to reconsider the current recommended daily values of vitamin D for older adults,” says Bess Dawson-Hughes, MD, author of the study. She adds, “We also need to look more closely at the possible role that calcium supplementation may have in mediating the effects of vitamin D. Fractures in the elderly can lead to severe health consequences, including death. One promising prevention strategy may be dietary supplementation with both calcium and vitamin D.”

Tufts University, Aug 9, 2005