June 15, 2012 -- Older people who take vitamin D with calcium may have lower death rates than those who don't.
That finding comes from a new study, published in the Journal of Clinical Endocrinology & Metabolism. It comes just days after an expert government panel reported that there is insufficient evidence to recommend calcium and vitamin D supplementation for older women.
The researchers analyzed findings from eight large vitamin D trials involving more than 70,000 older people.
People were followed for three years, on average. During that time, those who took vitamin D and calcium were less likely to die than people who did not.
The reason for the lower death rate isn't clear. But it didn't appear to be about a reduction in fractures, which is one main indication for taking calcium and vitamin D.
Vitamin D has been linked to a lower risk for colorectal cancers and several other cancers in some studies, but the research is far from conclusive.
"It seems that calcium with vitamin D has benefits for general health, but we need more studies to understand this association," researcher Lars Rejnmark, PhD, of Denmark's Aarhus University Hospital tells WebMD.
Vitamin D, Calcium Confusion
Earlier this week, the U.S. Preventive Services Task Force (USPSTF) recommended against postmenopausal women taking low doses of vitamin D and calcium for prevention of fractures.
Low dose was defined as 400 international units (IU) a day or less of vitamin D and 1,000 milligrams or less of calcium.
The panel found that at these doses there is little evidence of benefit and a slight increase in the risk for kidney stones.
Panelists concluded that there is insufficient evidence to recommend for or against taking larger doses of the supplements to prevent fractures or cancer.
The USPSTF recommendations and the new study findings add to the confusion surrounding who should take vitamin D and calcium supplements and at what doses.
Eat Right, Exercise to Lower Fracture Risk
Although the value of supplementation remains in question, it is clear that calcium and vitamin D obtained from food and exposure to sunlight can help protect against bone loss-related fractures as people age, says Connie M. Weaver, PhD, who directs Purdue University's Botanical Center for Age-Related Diseases.
Weaver adds that older people at risk for fractures should drink milk or eat yogurt and do weight-bearing exercise, if possible, to lower this risk.
"It is true that many people don't consume three cups of milk a day or the equivalent, and they may need supplements," she says.
In the newly reported study, most supplement users took 400 or 800 IU of vitamin D a day and 1,000 milligrams of calcium.
During the three years of follow-up, deaths were reduced by about 9% among people who took vitamin D and calcium.
The study appears today in the August issue of the Journal of Clinical Endocrinology and Metabolism, which is published by the Endocrine Society.