Vitamin C prevents hair loss as well as premature graying, dryness, and brittle hair. If you're not getting enough vitamin C from your diet, you should take a supplement to make sure you're getting enough.
Vitamin E helps to prevent and reverse hair loss thank to its ability to grow new blood vessels and increase circulation to the scalp. Topical vitamin E applied to the scalp may also help to regrow hair.
Vitamin D is beneficial for the whole body and this includes the scalp and hair. Also, vitamin D is necessary in order for the body to absorb calcium, which is essential for healthy follicles.
A vitamin A deficiency can lead to dry hair which can contribute to hair loss. Vitamin A stimulates the hair follicles and helps the scalp to produce sebum, which keeps the scalp and hair hydrated.