Solgar Folacin (Folic Acid) 400 µg, also known as Vitamin B9, contributes to several processes within the body, but is best known for its support of maternal tissue growth during pregnancy. ✓ SUPPORTS MATERNAL TISSUE GROWTH - Folacin (Folic Acid) 400 mcg, also known as Vitamin B9, contributes to several processes within the body, but is best known for its support of maternal tissue growth during pregnancy.