Mixed Long-term Effects of Calcium and Vitamin D in Postmenopausal Women

Jack Cush, MD

Mar 11, 2024 5:53 pm

A follow-up analysis of a randomized clinical trial found that the use of calcium and vitamin D supplements among postmenopausal women was associated with decreased risk for cancer mortality, but increased risk for cardiovascular disease (CVD) mortality. The analysis is published in Annals of Internal Medicine.

A multicenter US trial of 36 282 postmenopausal women randomized 1:1 to either 1000 mg of calcium carbonate (400 mg of elemental calcium) with 400 IU of vitamin D3 daily (CaD group) or placebo. This study was a post hoc analysis of long-term (7-year) followup data and examined rates of colorectal, invasive breast, and total cancer; disease-specific and all-cause mortality; total cardiovascular disease (CVD); and hip fracture.

Compared to placebo, those treated with CaD experienced:

7% decrease in cancer mortality (HR 0.93; 95% CI, 0.87 to 0.99)
6% increase in CVD mortality (HR 1.06; 1.01 to 1.12)
No effect on all-cause mortality (HR, 1.00)

Hip fracture and CVD outcomes were available on only a subset of participants, and effects of calcium versus vitamin D versus joint supplementation could not be disentangled.

Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women

Join The Discussion

I recommend pure vitamin D3 supplementation if there is insufficiency (<30) or deficiency (<20), without any added calcium. There is previous data, and this article supports it again that too much calcium supplementation increases CV risk. This concern was published previously, several years ago. The most one should take of daily calcium supplementation, if any should be no more than 500 mg. The interesting paper would've been the benefits of pure vitamin D supplementation, without any added calcium.