Vitamin B and iron supplements can help prevent further hair loss or thinning hair. Vitamin B and iron deficiency are common culprits of hair loss, states Health.com. Vitamin D, as well as protein and omega-3 fatty acids, can also help promote thicker and stronger hair, according to WebMD.
Aside from supplements, protein, vitamin D and omega-3 fatty acids are also found in foods such as salmon, trout, avocado and walnuts, states WebMD. Protein is essential to thicker hair as the body may slow down hair growth if there is a lack of protein. Omega-3 fatty acids are also important in hair growth and is not produced naturally in the body. In addition to hair production, omega-3 fatty acids are also present in the scalp to keep hair and skin hydrated.