• Posted March 12, 2024

Vitamin D Plus Calcium: Good News, Bad News for Older Women

Women who've gone through menopause and hope that supplemental vitamin D plus calcium might shield them from disease may be disappointed by new data.

A follow-up analysis of data from the landmark Women's Health Initiative trial found the supplement combo lowered a woman's long-term odds of dying from cancer by 7%.

However, it also raised her odds of fatal heart disease by 6%.

The bottom line: there was "no net effect on all-cause mortality" among older women who took the supplement combo, the study authors said.

It's possible "that calcium supplements may increase calcification of coronary arteries, thus increasing cardiovascular disease mortality," said a team led by Cynthia Thomson, a professor of health promotion sciences at the University of Arizona in Tucson.

The findings were published March 11 in the Annals of Internal Medicine.

For years, many older women have popped a combination of calcium plus vitamin D to help strengthen their bones. Many may also wonder if the supplements cut their odds for two major killers, heart disease and cancer.

The Women's Health Initiative began enrolling tens of thousands of women as far back as 1991, and has tracked their health outcomes over subsequent decades.

In 2006, the first (seven-year) findings on the effects of calcium/vitamin D supplementation on women's health were announced; the results were "largely null," Thomson's group noted.

Could that result have changed decades later?

To find out, the Arizona team crunched the WHI numbers for outcomes more than 22 years on.

They found no overall benefit in terms of deaths to older women from any cause.

There was a slight benefit when it came to reducing a woman's odds for fatal cancers, but that was offset by a slightly heightened risk for heart-related death.

Besides those findings, daily calcium/vitamin D supplementation also resulted in higher kidney stone risk for older women, the researchers noted.

The daily supplement doses used by women in the WHI included 1,000 milligrams of calcium and 400 IU of vitamin D.

Overall, "calcium and vitamin D supplements seemed to reduce cancer mortality and increase cardiovascular disease mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality," Thomson's group concluded.

More information

There's more on the effects of vitamin D and health at the Mayo Clinic.

SOURCE: Annals of Internal Medicine, March 11, 2024