New Releases from NCBI BookshelfEvidence reviews for optimum folic acid supplementation dose before and during the first 12 weeks of pregnancy for those with a BMI 25 kg/m2 or more: Maternal and child nutrition: Evidence review B.​Evidence reviews for optimum folic acid supplementation dose before and during the first 12 weeks of pregnancy for those with a BMI 25 kg/m2 or more: Maternal and child nutrition: Evidence review B.