Calcium, vitamin D supplements raise doubts

This article originally appeared in the San Francisco Chronicle’s health section on March 13, 2013.

Dark, leafy greens like kale are good sources of dietary calcium. Photo: John Lee, SFC
Dark, leafy greens like kale are good sources of dietary calcium. Photo: John Lee, SFC

Taking calcium and vitamin D supplements to improve bone health has become standard practice for aging women in America. More than 60 percent of U.S. women over 60 do it, according to the latest data from the Centers for Disease Control and Prevention.

But recent research indicates that, for most women, it doesn’t help prevent bone fractures, and it may slightly increase the risk of developing kidney stones.

That was last month’s ruling from the U.S. Preventive Services Task Force, a nongovernmental panel of experts who reviewed several studies involving postmenopausal women taking the two dietary supplements.

The panel also said there’s not enough research to say whether the supplements are helpful to men or premenopausal women, and patients already diagnosed with osteoporosis should consult with their doctors.

The panel’s findings come on the heels of a 2012 German study in the journal Heart, which links calcium supplements to an increased risk of heart attack.

No one disputes that calcium – 1,000 milligrams a day for most adults, and 1,200 for older women – is good for overall health. Dairy foods and dark, leafy greens like kale, spinach and broccoli are all good sources of dietary calcium, which doesn’t come with the same potential risks as supplements.