Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy

Abstract

(N Engl J Med. 2024;390:143–153) Many maternal deaths across the globe are associated with hypertensive disorders of pregnancy (HDP), including pre-eclampsia. Many interventions to prevent and treat HDP have been developed, one of which is calcium supplementation. The World Health Organization (WHO) recommends calcium supplementation in individuals with low dietary calcium intake, which has been previously shown to reduce the risk of pre-eclampsia by more than 50%, as well as reducing the risk of preterm birth by 24%. Studies have additionally shown at small sample sizes that low-dose calcium compared with higher doses has similar benefits. Despite the WHO recommendation, few countries have implemented calcium regimens as part of routine prenatal care, and few studies have been done in large samples to validate its efficacy. This study was designed to assess low-dose calcium supplementation and its effect on the risk of pre-eclampsia and preterm birth in a large sample.