High Calcium Intake May Harm Women

Women with high intakes of calcium raise their risk of death from all causes, according to Michael Smith, North American Correspondent, MedPage Today.

However, Swedish women that have been studied for almost two decades show no risk of stroke from high calcium intake.

Many women, especially older ones, take calcium supplements. For years, the goal has been to avoid low calcium levels.

issues were clarified in the following ways:

“The primary outcome measures, based on registry data, were time to death from all causes, as well as from cardiovascular disease, ischemic heart disease, and stroke.

The researchers assessed diet by food frequency questionnaires, allowing an estimate of calcium intake, both from diet and supplements. Participants were divided into groups based on calcium intake – less than 600 mg a day, between 600 and 999 mg daily, from 1,000 through 1,399 mg a day, and 1,400 or more mg daily (about five 8-ounce glasses of cow’s milk).

All told, 11,944 women died, including 3,862 from cardiovascular disease, 1,932 from ischemic heart disease, and 1,100 from stroke.

Compared with women whose intake was between 600 and 999 mg day, they found dietary intakes of more than 1,400 mg a day were associated with higher death rates:

All causes: hazard ratio 1.40 (95% CI 1.17 to 1.67)
Cardiovascular disease: HR 1.49 (95% CI 1.09 to 2.02)
Ischemic heart disease: HR 2.14 (95% CI 1.48 to 3.09)

However, higher dietary intakes of more than 1,400 mg per day was not associated with a significantly increased risk for stroke (HR 0.73).

“The increase was moderate with a high dietary calcium intake without supplement use, but the combination of a high dietary calcium intake and calcium tablet use resulted in a more pronounced increase in mortality,” the authors stated.”

(Source reference: Michaëlsson K, et al “Long term calcium intake and rates of all cause and cardiovascular mortality: community based prospective longitudinal cohort study” BMJ 2013; 346: f228.)