Table 1.

Biological roles of the B vitamins.

Vitamin	Biological Function
B1 (thiamine)	cofactor for enzymes in glucose metabolism, amino acid catabolism, nucleotide synthesis, and fatty acid synthesis [11]
B2 (riboflavin)	precursor for flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) for cellular respiration [12]
B3 (nicotinamide)	precursor for nicotinamide adenine dinucleotide (NAD) utilized in biosynthetic pathways, energy metabolism, and protection from reactive oxygen species [13]
B5 (pantothenic acid)	precursor for coenzyme A (coA), an acyl-carrier required for the activity of many enzymes [14]
B6 (pyridoxine)	cofactor for over 150 enzymes involved mainly in amino acid synthesis and degradation [15]
B7 (biotin)	plays an essential role in carboxylation reactions [16] and also has many applications in laboratory research
B9 (folate)	substrate for nucleotide synthesis and methyl-donors in the one-carbon metabolism pathway [12]
B12 (cobalamin)	cofactor for enzymes in one-carbon metabolism and the propionate catabolic pathway [12]