A: Although vitamin deficiencies are known to cause hair loss, there is little scientific evidence that shows that vitamin supplementation, in an otherwise healthy individual eating a well balanced diet, can prevent hair loss or improve the quality of one’s existing hair.

In addition, taking too many vitamins can actually contribute to hair loss. Excess Vitamin A can cause hair shedding in a reversible process referred to as telogen effluvium.

Accutane, a medication used for cystic acne, is a derivative of vitamin A and can cause hair loss that may be permanent.

A: Yes, if they were effective in increasing testosterone then they may accelerate hair loss.