Analysis highlights health effects of calcium and vitamin D supplements in postmenopausal women

Researchers from the University of Arizona conducted a WHI trial of CaD supplement versus placebo to evaluate long-term health outcomes among postmenopausal women. The researchers looked for incidence of cancer, disease-specific and all-cause mortality, CVD, and hip fracture by randomization assignment. Analyses also were stratified on personal supplement use.

They found that women who were randomly assigned to take CaD supplements had a 7% lower risk of dying from cancer over about 22 years compared to those taking placebo. However, there was also a 6% higher risk of dying from CVD among those who took the supplements. The study didn't find any significant overall effect on other measures, including all-cause mortality.

The study also noted that cancer incidence seemed to depend on whether the women were already taking supplements before the study began and that the CVD mortality was higher among those taking the supplements.

The findings suggested that Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality.

Reference: Cynthia A. Thomson, PhD, RD, Aaron K. Aragaki, MS, Ross L. Prentice, PhD, Marcia L. Stefanick, PhD, JoAnn E. Manson, MD, MPH, DrPH, Jean Wactawski-Wende, PhD, Nelson B. Watts, MD, Linda Van Horn, PhD, RD, James M. Shikany, DrPH, Thomas E. Rohan, MBBS, PhD, DHSc, Dorothy S. Lane, MD, MPH, Robert A. Wild, MD, PhD, MPH, Rogelio Robles-Morales, MD, Aladdin H. Shadyab, PhD, MPH, Nazmus Saquib, MBBS, MPH, PhD, MBA, and Jane Cauley, DrPH; Journal: Annals of Internal Medicine; DOI: 10.7326/M23-2598