Report Sets Recommended Levels for Calcium and Vitamin D
January 6, 2010
Headlines about vitamin D and calcium appear regularly in the media, but the research about how much is enough—and how much is too much—is conflicting, leaving many consumers confused. Should people take dietary supplements of these nutrients? What are the risks of consuming too much?
The Institute of Medicine (IOM) has just released its recommended dietary intake levels for calcium and vitamin D, following months of investigation into existing research and published reports. The IOM review was initiated at the request of the governments of Canada and the United States.
The majority of North Americans are receiving adequate amounts of both vitamin D and calcium, according to the IOM. There is some evidence that adolescent girls might not be getting enough calcium, and some people over the age of 70 might need to increase their intake of calcium and vitamin D.
Both calcium and vitamin D are essential for skeletal growth and maintenance, and for avoiding poor bone health. Calcium is readily available through food sources, such as dairy products, fish with soft, edible bones like canned salmon and sardines, and vegetables like kale, broccoli and Chinese cabbage. Only a few foods naturally contain vitamin D, including fatty fish like salmon, mackerel and tuna. Fortified foods like some cereals and milk provide most of the vitamin D in American diets. Vitamin D is also produced by the body when skin is exposed to sunlight.
Concerns about high amounts of these two nutrients are legitimate, the IOM reports. High levels of calcium may contribute to the development of kidney stones, and excessive levels of vitamin D have been linked to damage to the kidneys and the heart.
"While it is too early to make definitive statements about the risks associated with routine high doses of vitamin D and calcium, people don't need more than the amounts established in this report," said A. Catharine Ross, Ph.D., chair of the IOM committee. "…[S]ome therapies [like hormone replacement therapy] that seemed to show promise for treating or preventing health problems ultimately did not work out and even caused harm."
The IOM report also noted that hundreds of studies show vitamin D might help to ward off conditions like cancer, heart disease, autoimmune diseases and diabetes. While these studies show that further research is important, they also often show conflicting or mixed results and do not prove that vitamin D can prevent or treat these conditions.
For more information about vitamin D and calcium recommendations from the Institute of Medicine of the National Academies, including a chart that shows the IOM's average daily requirements, recommended allowances, and upper intake levels for these two nutrients, please go to Report Brief: Dietary Reference Intakes for Calcium and Vitamin D.
Sources: Institute of Medicine; "Dietary Supplement Fact Sheet: Vitamin D," Office of Dietary Supplements, National Institutes of Health; and "Dietary Supplement Fact Sheet: Calcium," Office of Dietary Supplements, National Institutes of Health
