Prenatal vitamins can be an essential supplement to your diet during pregnancy. There is an old wives’ tale that these supplements alone make your hair grow faster, which is why women who are not pregnant might take prenatal vitamins.These supplements are intended for pregnant women only, and there is no proof they are healthy methods for natural hair growth.ertain vitamins and minerals promote overall hair health, many of which are available in prenatal vitamins. Dr. Melissa Piliang of the Cleveland Clinic notes in a June 2013 ''Huffington Post'' article that B vitamins, vitamin D, iron and zinc are good for your hair.