Folic acid, also known as Vitamin B9, is crucial to hair growth, responsible for regenerating the cells that regrow hair. Found naturally in the body and foods, folic acid may also be taken as a supplement, according to Mayo Clinic.
Taking vitamins cannot replace a good diet or give the energy provided by foods with essential vitamins in them, so proper dieting is the best way to get essential nutrients. Folic acid can be naturally found in foods such as spinach, oranges, grapefruit and legumes. Some packaged foods such as pastas and cereals are fortified with folic acid, says progressivehealth.com.