- a crystalline, water-soluble vitamin, C10H16O3N2S, of the vitamin B complex, that is present in all living cells and functions as a growth factor and as a catalyst in carboxylation reactions.
- a vitamin of the B complex, abundant in egg yolk and liver, deficiency of which causes dermatitis and loss of hair. Formula: C 10 H 16 N 2 O 3 S
