In a significant advancement for prenatal healthcare, two large-scale randomized trials have demonstrated that low-dose calcium supplementation is equally effective as high-dose supplementation in preventing preeclampsia in pregnant women, particularly in regions with low dietary calcium intake. Conducted in India and Tanzania, these trials, involving 22,000 nulliparous pregnant women, offer a promising alternative to the current high-dose regimen recommended by the World Health Organization (WHO).Â
The study, published in the New England Journal of Medicine, compared the efficacy of a daily 500 mg dose of calcium supplementation against the standard 1500 mg dose. The primary focus was on reducing the risk of preeclampsia, a condition characterized by high blood pressure and often leading to preterm births. Remarkably, the results showed that the lower dose was noninferior to the higher dose in both trials, marking a significant shift in prenatal nutrition strategy.Â
Involving 11,000 women from each country, the study’s findings were consistent across both geographies. In India, the incidence of preterm birth was lower in the 500 mg group compared to the 1500 mg group, aligning with the noninferiority criteria. However, in Tanzania, the results did not show noninferiority for preterm births, suggesting geographical variations in response to calcium supplementation.Â
This research holds immense potential for global maternal and child health. Preeclampsia complicates 2 to 8% of pregnancies worldwide and is a leading cause of maternal and infant mortality. By demonstrating the effectiveness of a lower calcium dose, the study paves the way for more accessible and affordable prenatal care, especially in low and middle-income countries where dietary calcium intake is typically low.Â
The WHO has long recommended high-dose calcium supplementation to reduce preeclampsia risk. However, the complexity and cost of the high-dose regimen have been significant barriers to its widespread implementation. The current findings challenge this approach, suggesting that a single 500 mg tablet per day could be just as effective. This simpler regimen could improve adherence among pregnant women and reduce the financial burden on healthcare systems.Â
The trials also assessed safety outcomes, including maternal hospitalization and severe anemia, along with secondary outcomes like gestational hypertension and infant mortality. The results showed no significant difference between the low and high-dose groups, reinforcing the safety of the lower dosage.Â
These findings could revolutionize prenatal care guidelines globally. The reduced pill burden and lower cost of a 500 mg calcium supplement make it a more practical option for pregnant women, especially in regions where healthcare resources are limited. Additionally, the study highlights the need for personalized prenatal care, considering geographical and dietary variations.Â
While the study’s large scale and randomized design lend it considerable credibility, it’s important to note that it focused solely on nulliparous women (women who have not given birth before) and did not include a placebo group. Further research is needed to explore the effectiveness of low-dose calcium supplementation in a broader demographic and in comparison to no supplementation.Â
The groundbreaking results from these trials in India and Tanzania are a beacon of hope for improving maternal and child health outcomes worldwide. By demonstrating that low-dose calcium supplementation is noninferior to the high-dose regimen in preventing preeclampsia, this research offers a simpler, more cost-effective approach to prenatal care. As the global health community continues to strive for better maternal and child health outcomes, these findings could play a crucial role in shaping future prenatal care practices.Â
Journal Reference –Dwarkanath, P., Muhihi, A., Sudfeld, C. R., Wylie, B. J., Wang, M., Perumal, N., … Fawzi, W. W. (2024). New England Journal of Medicine, 390(2), 143–153. doi:10.1056/nejmoa2307212
