Who isn't a fan of long and thick hair? We all are as hair is an important ornament that we wear. Thinning hair and waking up with strands of hair on our pillow troubles us.
We must know that healthy hair can be acquired only when we are sufficient in the vitamins and minerals associated with hair health. The vitamins essential for hair growth will be discussed below.
The first thing that strikes our mind when we think of Vitamin A is eye health. But we must know that Vitamin A also performs an important role in hair health. Vitamin A helps in the formation of sebum, an oily substance which keeps our hair healthy.
It has also been noted that deficiency of this vitamin leads to hair fall.
Among the B Vitamins, Biotin is mostly discussed when it comes to hair health. Since ages it's been used as a hair fall expert. There have been studies conducted especially to prove this fact. Biotin helps in the production of keratin and stimulates the growth of the follicles. Because of this very reason biotin deficiency is associated with hair loss. Biotin supplementation showed improvement in hair health in various studies.  Apart from this. Biotin supplementation was found to be helpful in reducing hair loss in several disease conditions.
A particular study conducted on individuals suffering from uncombable hair syndrome showed that when supplemented with biotin showed better hair results. 
Vitamin C is not an alien to us, isn't it? We have also known it for its wonderful effect on skin and overall health. Apart from being a powerful antioxidant Vitamin A a.k.a ascorbic acid plays an important role in the absorption of iron in the intestine. This is because of their chelating and reducing property. That's the reason why your Doctor suggests you take Vitamin C along with your iron supplements. Therefore Vitamin C helps in reducing the incidence of hair loss due to iron deficiency. 
Vitamin D has been found to play an important role in the hair follicle cycle. Its role in the proliferation and differentiation of keratinocytes is widely accepted and known by dermatologists. 
Vitamin D deficiency is also observed in scarring alopecia (collection of hair loss disorder which is diagnosed upto 3% in hair loss patients). There are many studies which show the relationship between Vitamin D and hair growth but enough studies proving that supplementation can be helpful in treating hair loss has been lacking.
Vitamin E is a powerful antioxidant and a fat soluble vitamin with the ability to penetrate to a precise site in the cell membrane. This is an important attribute which accounts for its function for hair growth.
A particular study showed that supplementation with Vitamin E helped in the hair growth among individuals suffering from alopecia than on the placebo. They suggested that this may be due to the antioxidant properties of Vitamin E which helped fight the oxidative stress in the scalp among individuals with alopecia. 
Many vitamins are responsible for giving you the best hair you deserve. Being sufficient in above vitamins ensures a healthy hair. Therefore one must consume enough of it through diet or can opt for supplements