This unique, high quality formula contains the most biologically active forms of many B-vitamins including Quatrefolic® acid and B12 in the form of methylcobalamin. B-vitamins play many important roles in the body. For example, vitamin B12 and folic acid are crucial for proper cell division; vitamins B1, B2, B3 and biotin are essential for energy production. Amino acid metabolism requires vitamin B6. Vitamin B5 is necessary for the synthesis of acetylcholine (a neurotransmitter) and is also involved with energy production. Some B vitamins have been shown to play a role in wound healing and vitiligo. Biotin is known to improve nail strength.