Newsletters

Winter 2011

Calcium and Vitamin D in the News

With advances in science, healthcare guidelines often change. Sometimes new guidelines appear to be in conflict with old ones, and different organizations develop different guidelines for the same condition. So it is with calcium and vitamin D.

The latest recommendations for daily calcium and vitamin D intake were released in November 2010 by the Institute of Medicine (IOM). The IOM has an advisory role on healthcare issues for the US federal government, and in this case, for Canada as well. A committee of experts reviewed the evidence in over 1000 scientific papers and listened to testimony from scientists and stakeholders before reaching conclusions that were surprising and provocative. The recommendations of the IOM are important because they are widely used by government agencies for activities such as setting standards for school meals and specifying the nutrition label on food products.

The IOM report, which can be obtained at www.iom.org, stated that most Americans are currently getting adequate amounts of calcium and vitamin D, with the notable exception of girls age 9-18, who often do not get enough calcium. This is contrary to the popular belief, supported by medical research, that many or most of us have a deficient intake of calcium and vitamin D. The IOM also stated that there is emerging evidence that excessive intake of calcium and vitamin D may be harmful. It was found that these nutrients were important for skeletal health, while the evidence that they were helpful for other conditions, such as prevention of cancer and improved muscle strength, was felt to be inconclusive. Excessive calcium might increase the risk of kidney stones and too much vitamin D could cause kidney problems.

The recommended calcium and vitamin D intake and the maximum safe intake varied by age. For example, for women age 51-70, the recommendation for calcium was 1200 mg/day (maximum 2000 mg/day), with vitamin D 600 IU/day (maximum 4,000 IU/day). These values are similar to what is recommended by the National Osteoporosis Foundation (NOF), with the principal exception that the NOF suggests a target vitamin D blood level of at least 30 ng/ml, while the IOM uses a value of 20 ng/ml.

What are we to do with these recommendations? First, remember that these are guidelines for the general public, not “laws” for every individual person. Some of us may need more or less than the recommended intake, depending on our needs. Dietary intake of calcium and vitamin D from sunlight must also be considered. Second, just because something is good for you does not always mean that more is better. Too much of almost anything in life may be harmful. Finally, work with your physician to determine what is best for you.

E. Michael Lewiecki, MD                                    
Lance A. Rudolph, MD

This page update 02/27/11