The B complex vitamins, including B6, B12, and folic acid, are vital for hair growth. They play a significant role in red blood cell production, which provides oxygen to the scalp and hair follicles, aiding in hair growth and health. Deficiencies in these vitamins can lead to hair loss, which underscores their importance.
Reference: Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. "The Role of Vitamins and Minerals in Hair Loss: A Review." Dermatology and Therapy, 2019.