Thinning hair and hair loss can be devastating, whether caused by heredity, diet, stress, pregnancy or medical treatment. For most of us, our hair color, length and style is an essential part of our self-image, so losing it can greatly affect our confidence and self-esteem. While medical procedures to restore hair loss are available, these can be expensive and, in some cases, risky. Instead, many people opt for hair growth supplements. Vitamins and nutrients that promote hair growth include vitamins A and E, Niacin, Folic Acid, Biotin and Zinc.