Interplay Between Vitamin D Levels and Heavy Metals Exposure in Pregnancy and Childbirth: A Systematic Review.

Background/objectives: Vitamin D (VD) deficiency has been associated with increased risk of gestational disorders affecting the endocrine system, immune system, and neurodevelopment in offspring. Recent studies have focused on the interaction between toxic elements and micronutrients during pregnancy. This review analyzes the potential relationships between VD levels and heavy metals in pregnant women and their offspring.

Methods: A systematic review was conducted according to PRISMA 2020 guidelines, using databases such as PubMed, ScienceDirect, Cochrane Library, and Google Scholar. Boolean operators 'AND' and 'OR' were applied with terms like 'pregnancy', 'vitamin D', 'heavy metals', and 'newborns'.

Results: From 4688 articles, 14 studies were selected based on relevance and quality. These studies measured the levels of metals like lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As), in biological samples including maternal blood, umbilical cord blood, placenta tissue, and meconium during different stages of pregnancy, showing an inverse relationship between VD deficiency and heavy metal concentrations, which could be related to the incidence of preterm birth.

Conclusions: The review highlights the importance of maintaining adequate VD levels during pregnancy, suggesting that sufficient VD may mitigate the adverse effects of heavy metal exposure, potentially reducing pregnancy-related complications.