Calcium supplementation in pregnancy as a strategy to prevent pre-eclampsia: a narrative review of current clinical evidence

Abstract

Hypertensive disorders are currently the most prevalent gestational comorbidities, with preeclampsia affecting up to 8% of pregnancies. Therefore, strategies to reduce its incidence are necessary to mitigate the risks to maternal and infant health. This study aims to identify whether calcium supplementation during pregnancy, as recommended by the Brazilian Ministry of Health in 2025, is an appropriate strategy for this purpose. This is a narrative review of the current literature available in the PubMed and Biblioteca Virtual em Saúde databases between 2018 and 2025, including literature reviews or meta-analyses. In total, 11 articles and the Brazilian Technical Note No. 251/2024 were included. Upon evaluating these sources, it is evident that calcium supplementation during pregnancy reduces the risk of preeclampsia, especially among women living in areas with low dietary calcium intake. There is no consensus on the minimum daily dose required; however, studies show benefits with supplementation ranging from 120 to 2,000 mg/day. Some studies also suggest secondary benefits, such as reduced maternal mortality. Despite the favorable evidence, further studies are needed to compare universal versus targeted supplementation doses and to assess potential risks associated with the inadvertent intake of calcium.