Depends. There is little evidence of the effectiveness of vitamin supplements formulated for hair, skin, and nails. However, they may be beneficial to mitigate potential deficiencies that may impact their health and appearance. Supplementation, overseen by a doctor, may work in these cases. Depends. There is little evidence of the effectiveness of vitamin supplements formulated for hair, skin, and nails. However, they may be beneficial to mitigate potential deficiencies that may impact their health and appearance. Supplementation, overseen by a doctor, may work in these cases.