There are several B vitamins that are good for your hair. The one that is widely known for being conducive to healthy hair is called biotin, or B7. Biotin strengthens hair and prevents it from getting thin and brittle and also increases hair growth. It protects the roots. This particular vitamin is water-soluble, so it safe to take in relatively higher doses. You can find biotin in eggs, nuts, berries and fish.
B6 is another vitamin that promotes hair health. It binds to testosterone and so keeps that hormone from damaging your hair. You can find B6 in avocados, eggs, legumes, whole grains and, of course, you can also take it as a supplement.
B9 is also known as folic acid and it influences the metabolism of biotin, so it helps you make fuller use of biotin. This one is, therefore, on the list of vitamins helpful to keeping your hair thick and strong.
Niacin, also called B3, helps nutrients make their way to your hair. So, this one too will aid the hair in staying in good shape and looking good too.