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How Much Vitamin D — or Calcium — Do You Need?

Recommendations say more D, but maybe less calcium, than you're taking

A report from the Institute of Medicine setting new guidelines for vitamin D and calcium increases the recommended levels of D, but maintains or decreases the recommended levels for calcium.

Most Americans and Canadians, the report states, are getting enough vitamin D and calcium, although older men and women may fall short.

Vitamin D

Adults up to age 70 need 600 IU (international units) daily, up from 400 IU in 1997.

Men and women 71 and older need 800 IU, up from 600 IU.


Men need 1,000 mg daily until age 71, down from 1,200 mg in 1997.

Women, beginning at age 51, and both men and women over age 71, need 1,200 mg of calcium a day, the same as in 1997.

The 2010 recommendations update those set in 1997. 

The report also notes that taking more than 4,000 IU of vitamin D daily (up from 2,000 IU) or 2,000 mg of calcium daily (down from 2,500 mg) increases the risk for harm.

In the years since the first report was published, studies have linked these two nutrients, both individually and combined, to a potentially wide range of benefits, including lower blood pressure, reduced risk of bone fracture and decreased risk of some infections, as well as protection against heart disease, Parkinson's disease and type 2 diabetes.

As a result, some scientists have called for high levels of vitamin D from supplements, anywhere from 1,000 to 2,000 IU a day, in addition to sun exposure, fortified foods and multivitamins.

Although the report confirms the role of calcium and vitamin D for bone health, it points out that studies of vitamin D for other health problems have yielded conflicting and mixed results and that definitive studies are needed.

Very high levels of vitamin D (above 10,000 IU a day) may cause kidney and tissue damage. Evidence of risks at lower levels is limited, but some studies offer tentative signals about adverse health effects. The report also notes that standards for vitamin D blood test results have not been based on rigorous studies and could lead to doctors diagnosing vitamin D deficiency when people have enough.

“The current recommendations for calcium intake are sound, and food sources of calcium are preferred over supplements. The IOM recommendations for vitamin D are reasonable for the general population, pending definitive evidence that more vitamin D is beneficial," says Bess Dawson-Hughes, M.D., director of the Bone Metabolism Laboratory at the Human Nutrition Research Center on Aging at Tufts University. 

Her bottom line advice: In general, older people can achieve healthy levels of vitamin D by taking the recommended 800 IU of vitamin D a day and they don’t need to be tested. 

“But if you fall into a high-risk group, you likely need more than that,” says Dawson-Hughes, who was not involved in the report. People who spend little time in the sun, use sunscreen whenever they go outside, have dark skin or are overweight are among those considered high-risk. "These men and women should be tested,” she adds.

If the new recommendations leave you confused, you're not alone. Keep in mind that these numbers are important for developing national nutritional guidelines for food programs. When it comes to your own health, you might want to have a heart-to-heart talk with your doctor.