Americans spent more than $1 billion on calcium supplements and $831 million on vitamin D supplements in 2015, according to data from the Nutrition Business Journal.

“Many consumers, especially older people who are concerned about bone loss, buy and take calcium and vitamin D pills expecting them to strengthen their bones and prevent fractures,” says Consumer Reports' chief medical adviser, Marvin M. Lipman, M.D.

Are they getting their money's worth? We looked at the research to find out if you need the supplements, or are better off getting those nutrients from a healthy diet.

Calcium Supplements

Taking daily calcium pills can increase bone density in people over 50 years old by 1 to 2 percent—not enough to prevent fractures. That’s according to a review of 59 randomized controlled trials, published last year in the British Medical Journal. “That small gain is not worth the risks, including an increased likelihood of heart disease, kidney stones, and gastrointestinal problems,” Lipman says.

Vitamin D Supplements

Taking vitamin D alone does not appear to build bone. For example, a study of 159 postmenopausal women published in the Journal of Clinical Endocrinology & Metabolism in 2013 found that markers that may indicate osteoporosis declined significantly for people who took calcium supplements, but were unchanged for those who took only vitamin D.

Still, vitamin D might help prevent fractures in older people by reducing the risk of falls, according to the 2012 recommendations from the independent U.S. Preventive Services Task Force. It’s not clear exactly how vitamin D might prevent falls, but one theory is that very low levels of vitamin D has been linked with muscle weakness, and boosting levels back up may restore muscle strength.

“The key is developing strong bones early in life—before age 30 when our bones naturally start to thin,” Lipman says. “After 30, it’s a matter of preserving bone strength by consuming enough calcium in your daily diet so that the body doesn’t take what it needs from the bones,” he says.

What to Do Instead

Teens need at least 1,300 mg of calcium daily, according to the Institute of Medicine. That’s when bones are forming. After age 30, get at least 1,000 mg of calcium and 800 IU of vitamin D daily to slow bone loss.

The best way to get that calcium is to eat calcium-rich foods including milk, cheese, and yogurt. Good sources of vitamin D are mushrooms, eggs, fortified milk, soy beverages, and salmon. Our bodies also make vitamin D when our skin is exposed to sunlight, so our experts suggest getting 10 minutes of sunshine per day.  

Exercise is important, too. “Weight-bearing aerobic activities, such as walking and dancing, may slow bone loss. Aim for 30 minutes each day, even if it’s just a brisk walk,” Lipman says.