Proposed recommendations question the value of calcium, vitamin D supplements

The U.S. Preventive Services Task Force (USPSTF) has stirred up a maelstrom of debate by proposing that healthy postmenopausal women lay off daily calcium and vitamin D supplements, which the task force says may do more harm than good. If your doctor has recommended these supplements to protect your bones, you might feel like you’re on a see-saw of advice and can’t tell which end is up.

Before tossing your supplements in the trash, you need to understand the USPSTF’s rationale for the advice, and how osteoporosis specialists are advising their patients in light of this recommendation. Three Harvard doctors offer their perspectives on the issue.

The rationale

The USPSTF makes its recommendations by weighing the available evidence on the benefits of any particular preventive practice against its risks. In this case, they examined studies that assessed the ability of calcium and vitamin D supplements to protect against osteoporosis-related bone fractures and cancer, and their odds of causing side effects.

They concluded that, based on the available evidence, supplements containing up to 400 IU of vitamin D and 1,000 milligrams (mg) of calcium don’t reduce fractures in postmenopausal women. Plus, these supplements may slightly increase the risk of kidney stones. (Calcium supplements have also been linked to a higher risk of heart disease.)

As a result, the USPSTF says that postmenopausal women who aren’t at risk for osteoporosis shouldn’t be taking these supplements to prevent fractures. The jury is still out on whether it’s worth it for women and men to take higher doses of calcium and vitamin D to prevent fractures, or to take vitamin D to prevent cancer.

To supplement…or not to supplement?

Before changing your daily supplement regimen, remember that these recommendations are still preliminary. The USPSTF has submitted its recommendation in draft form, hoping to hear from experts in the medical community. The feedback it gets could alter the final recommendations.

Also, the recommendations may not apply to you. “We have to remember that these are draft recommendations and evidence is lacking at this time for many of those recommendations,” explains Dr. Jill Paulson, instructor in medicine at Harvard Medical School. “It is not one-size-fits-all and it is not a blanket statement.”

The recommendations also don’t apply to those who have osteoporosis or who are at risk for it. “I am going to continue to recommend that those patients get adequate calcium and vitamin D,” Dr. Paulson says.

The Institute of Medicine recommends that all women over age 50 need 1,200 mg of calcium a day; those aged 51 to 70 need 600 international units (IU) of vitamin D, while those over age 70 need 800 IU. Men aged 51 to 70 years need 1,000 mg of calcium and 600 IU of vitamin D, while those over age 70 need 1,200 mg of calcium and 800 IU of vitamin D. Our experts say most of those daily requirements should come from your kitchen, not your medicine chest.

“I think calcium and vitamin D are important for bone health, but I recommend that patients get calcium from their diet,” explains Dr. Meryl LeBoff, director of the Skeletal Health and Osteoporosis Center and Bone Density Unit at Brigham and Women’s Hospital and professor of medicine at Harvard Medical School. “In individuals who can’t meet the dietary recommendations, I would recommend supplements.”

“I tell patients to estimate the amount of calcium they are getting from their diet and then supplement it. I don’t want them to take excess calcium,” adds Dr. David Slovik, associate professor of medicine at Harvard Medical School, chief of the Endocrine and Diabetes Unit at Newton-Wellesley Hospital, and endocrinologist at Massachusetts General Hospital.

Getting your daily requirement of calcium is easier than you think—and it doesn’t require chugging gallons of milk. Good sources of calcium include:

• low-fat yogurt (8 ounces, 400 mg)
• calcium fortified orange juice (8 ounces, 400 mg)
• Cheddar cheese (1.5 ounces, 180 mg)
• canned salmon and sardines (3 ounces, about 300 mg)
• collard greens and spinach (1 cup, about 250 mg)

Reaching your daily vitamin D requirement with food is challenging, because only a few foods contain large amounts of vitamin D. Good choices include:

• salmon, trout, halibut, tuna, and sardines (3 ounces, 250 mg to 400 mg)
• milk, cheese, and other dairy foods (30 IU to 60 IU per serving)
• fortified orange juice and breakfast cereal (40 IU to 60 IU per serving)

(Extensive lists of good food sources of calcium and vitamin D are available for free from the USDA’s Agricultural Research Service.)

Vitamin D is also activated in sun-exposed skin, but “in the winter in northern climates, there’s very little activation of vitamin D in the skin,” Dr. LeBoff says. That’s why many doctors recommend vitamin D supplements.

So don’t drop your supplement regimen based solely on the USPSTF’s recommendations. You could neglect your bones in the process. “Review the specific recommendations with your doctor, because these are important health decisions,” Dr. LeBoff advises.