According to a new study published in the New England Journal of Medicine, vitamin D appears to have a stronger role in protecting bones than previously thought. Researchers analyzed the results of 11 double-blind, randomized, controlled trials of oral vitamin D supplements that involved various dosing schedules (such as daily, weekly, or every 4 month dosages), with or without calcium and compared with a placebo or calcium alone, all in people 65 and older—the age group that suffers 75 percent of all fractures. In all, the studies they looked at represented more than 31,000 people.
The researchers found that the dose of vitamin D was the key determinant—taking between 800 and 2000 international units (IU) of vitamin D every day reduced the risk of hip fracture by up to 30 percent and the risk of other bone fractures by up to 14 percent. Lower doses, with or without calcium, seemed to have a negligible effect, which is why some earlier individual studies hadn’t found a benefit—the vitamin D doses used was too low to make a difference.
In sunny climates, getting vitamin D is often easy—just 10 to 20 minutes in the sun. The problem with that is the potential skin cancer risk, since the exposure should be unprotected. Vitamin D is found in egg yolks, some fatty fish like tuna and salmon and fortified milk (read the label—just one glass may give you 200 IU), and if you take a daily multivitamin, it may deliver 400 IU. Once you add up your daily D intake, ask your doctor if a vitamin D supplement is in order. And definitely don’t go overboard—too much D can be hazardous to your health.