Power of Calcium Keeps Women Living Long

Calcium supplements up to 1000 milligrams linked to reduced mortality in women

(RxWiki News) Calcium helps maintain strong bones. But that's not the only benefit of this nutrient. New research suggests that calcium supplements may extend women's lives.

A recent study showed that taking up to 1,000 milligrams per day of a calcium supplement could help women live longer.

Based on their findings, the researchers recommended that consumers have their dietary intake assessed to ensure their calcium and vitamin D levels meet the requirements for good bone health.

Vitamin D is responsible for absorbing calcium. The two nutrients together contribute to strong bone growth and development.

"Vitamin deficient? Speak with a pharmacist."

The study, led by Lisa Langsetmo, PhD, from the CaMos National Coordinating Centre at McGill University in Montreal, Canada, looked at the links between calcium and vitamin D intake and mortality, or the risk of dying.

More than 9,000 participants with adequate calcium and vitamin D intake were included in the study. Participants were part of the Canadian Multicenter Osteoporosis Study (CaMos) over a 10-year period beginning in 1995.

Participants were at least 25 years old and lived within a 50-kilometer radius of one of nine Canadian cities. Almost 70 percent of the participants were women.

The participants were selected randomly through telephone calls. A greater number of women and older individuals were selected to ensure those population had enough data.

Each of the participants was surveyed on their dietary calcium and vitamin D intake.

In general, men and women over the age of 50 need at least 1,200 milligrams of calcium a day and 800 to 1,000 international units (IUs) of vitamin D.

About 15 percent of the women and 7 percent of the men used calcium supplements alone, and 3.7 percent of women and 4.4 percent of men used vitamin D supplements alone.

A total of 29 percent of women and 15.4 percent of men used both supplements together.

The survey covered food sources high in calcium, including milk, milk products and other foods, such as broccoli, dried peas or beans, canned salmon, dark leafy greens, whole wheat bread, white bread and tofu.

The researchers also took participants' height, weight, medical history, medication use, nutrition and demographics into account.

A separate survey covering participants' medications and whether they had any fractures was mailed each year, excluding the years that patients had a follow-up visit.

The researchers contacted participants each year throughout the study and screened obituaries for participants who could not be located.

Over the 10-year period, the researchers found that 1,160 people died.

For each 500 milligram increase in daily calcium intake up to 1,000 milligrams, the risk of dying early decreased by 5 percent compared to women who didn’t take the supplements, the researchers found.

The researchers could not find any links between calcium supplement usage and risk of dying among men.

Taking vitamin D supplements was not linked with a lowered chance of dying among both men and women.

"We found that after adjustment for all risk factors including concurrent use of calcium supplements, vitamin D supplements were not associated with reduced mortality risk in women," the researchers wrote in their report.

"Thus neither major vitamin sources studied (milk and supplements) were associated with mortality. This result is consistent with a recent meta-analysis of calcium and vitamin D supplement trials which found reduced mortality with calcium and vitamin D supplements combined, but not with vitamin D supplements alone," they wrote.

Previous research on calcium supplementation has drawn mixed conclusions. A study published by JAMA in February found that a high intake of calcium supplements might be linked with an increased risk of heart disease and death in men but not women.

A 2010 report by the Institute of Medicine concluded that with calcium and vitamin D supplementation, "...higher levels have not been shown to confer greater benefits, and in fact, they have been linked to other health problems."

Given the results of previous studies, it is hard to draw any strong conclusions, according to Jason Poquette, BPharm, RPh, a registered pharmacist and dailyRx Contributing Expert.

"I personally recommend patients talk to their physician about their diet, about their risk for developing osteoporosis, and about whether calcium supplementation is necessary," he said.

If calcium supplements are needed, Dr. Poquette recommends taking no more than 600 milligrams per dose complimented with a vitamin D supplement, since calcium absorption depends on sufficient levels of vitamin D.

The authors noted they had a low response rate to their research, which may have subjected their findings to bias. In addition, the low cohort size and death rate might have limited the ability to detect links between calcium or vitamin D uptake.

The study will be published in the July issue of the Journal of Clinical Endocrinology & Metabolism (JCEM).

The Canadian Multicenter Osteoporosis Study received funding from the Canadian Institutes of Health Research (CIHR), Amgen, Merck Frosst Canada Ltd, the Dairy Farmers of Canada, Novartis and Eli LIlly and Co.

Reviewed by: 
Review Date: 
May 24, 2013