Association between micronutrient supplementation during pregnancy and preterm birth: evidence from a large-scale children survey and Mendelian randomization study

Combining observational data with genetic causal inference, our study confirms the protective roles of folic acid, calcium, and iron against PTB, with MR particularly highlighting calcium's causal association with reduced PTB risk. These findings provide a comprehensive understanding and underscore the importance of targeted nutritional interventions, especially calcium, in prenatal care for PTB prevention. However, given the limitations of the self-reported data and the lack of information on doses used in our study, future prospective studies with more detailed micronutrient information are needed to provide more comprehensive evidence.