While strands of hair are actually just life-less protein fibers, the hair follicles under your skin are very much alive. Hair follicles need a supply of nutrients like other parts of the body. Some of these nutrients critical hair nutrients include: protein, carbohydrates, EFAs (fatty acids), vitamins B6 and B12, biotin, and iron.
Stress, illnesses and hormone imbalances can also affect your hair in a negative way, which is why some women do tend to lose their hair in times of high stress. Female hormones (progesterone and estrogen) promote thick, healthy hair, while male hormones can cause hair loss or thinning hair. So, if you needed yet another reason to eat better and stress less, keep in mind that your hair health is affected by what goes in your body, too.