Calcium and Vitamin D Supplements in Postmenopausal Women Reduce Cancer Mortality, reveals study

A recent post hoc analysis of the Women's Health Initiative CaD trial found calcium and vitamin D (CaD) to reduce cancer mortality among the postmenopausal women. The key highlights were published in the Annals of Internal Medicine. 

The findings of this research suggest that while calcium and vitamin D supplementation may have an impact on chronic diseases in older women, the evidence regarding its long-term effects on health outcomes remains limited. The multicenter trial was conducted across 40 locations in the US and included the participants with no history of breast or colorectal cancer. Over 36,000 women were randomly assigned to either receive 1000 mg of calcium carbonate with 400 IU of vitamin D3 daily or a placebo.

After a median cumulative follow-up of 22.3 years, this research observed a 7% reduction in the cancer mortality among the women who received CaD supplements when compared to the placebo group. However, there was also a 6% increase in cardiovascular disease (CVD) mortality among the CaD group.

The study did not find any overall effect on all-cause mortality, although the estimates for cancer incidence varied depending on whether participants reported supplement use before randomization. The outcomes such as hip fracture and CVD were only noticed in a subset of participants and the effects of calcium versus vitamin D versus joint supplementation could not be fully distinguished. Overall, the calcium and vitamin D supplements appeared to have long-term effects on the postmenopausal women's health, with a reduction in cancer mortality but an increase in CVD mortality.

Reference:

Thomson, C. A., Aragaki, A. K., Prentice, R. L., Stefanick, M. L., Manson, J. E., Wactawski-Wende, J., Watts, N. B., Van Horn, L., Shikany, J. M., Rohan, T. E., Lane, D. S., Wild, R. A., Robles-Morales, R., Shadyab, A. H., Saquib, N., & Cauley, J. (2024). Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women. In Annals of Internal Medicine. American College of Physicians. https://doi.org/10.7326/m23-2598