Many people view healthy-looking hair as a sign of health or beauty. Like any other part of your body, hair needs a variety of nutrients to be healthy and grow (1Trusted Source). In fact, many nutritional deficiencies are linked to hair loss. While factors such as age, genetics and hormones also affect hair growth, optimal nutrient intake is key. Below are 5 vitamins and 3 other nutrients that may be important for hair growth. 1. Vitamin A All cells need vitamin A for growth. This includes hair, the fastest growing tissue in the human body. Vitamin A also helps skin glands make an oily substance called sebum. Sebum moisturizes the scalp and helps keep hair healthy (2Trusted Source). Diets deficient in vitamin A may lead to several problems, including hair loss (3Trusted Source). While it's important to get enough vitamin A, too much may be dangerous. Studies show that an overdose of vitamin A can also contribute to hair loss (4Trusted Source).