Vitamins A, B, C and E can be taken to stimulate hair growth, according to BeautyHigh.com. Individuals taking vitamin supplements on a daily basis tend to see results within two to three months from the date of first ingestion.
Individuals can also achieve longer tresses by consuming certain vitamin-rich foods. Sweet potatoes offer a significant amount of vitamin A to the body, which is not only important for hair growth but also overall health, explains WebMD. Spinach, which contains vitamin C, helps to circulate oils on the scalp, giving the roots an extra boost for hair growth.