The impact of Vitamin D supplementation and sun exposure on pregnant women's health has been revealed in a randomized controlled trial published in the “Iranian Journal of Public Health”. The study, which included 108 pregnant women in Semarang, Indonesia, found that both Vitamin D supplementation and sun exposure considerably increased Calcidiol levels and birth weights. The Vitamin D group, receiving a daily 1000 IU supplement, experienced not only elevated Calcidiol levels but also maintained systolic blood pressure (BP).

The study participants were randomly allocated to three groups: sunlight exposure, Vitamin D supplementation (those who receive 1000 IU every day), and a control group. Those in the sunlight exposure group were recommended to spend 15 to 30 minutes in the sun thrice weekly for 17 weeks. Before the intervention, all groups exhibited Vitamin D deficiency and varying levels of Calcidiol, systolic, and diastolic BPs.

Later, both sun exposure and Vitamin D groups showed increased mean Calcidiol levels. Remarkably, systolic BP decreased substantially in the Vitamin D supplementation group.

The most notable finding was the positive impact on newborns. The Vitamin D group had the highest mean birth weight when compared to the sun-exposed and control groups, as shown in Table 1:

Further research is needed to explore the long-term effects and potential applications of these findings in maternal care.