Prenatal vitamins are multivitamins intended for women who are pregnant or hope to become pregnant. Sometimes
prenatal vitamins are recommended for women who are
breast-feeding, too. Most
prenatal vitamins contain more folic acid, iron and calcium than do standard adult multivitamins. Prenatal vitamins have been claimed to promote thicker hair and stronger nails, but researchers haven't yet proved whether prenatal vitamins truly have these effects.