Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C).
Related Theory
Vitamin $B_1 \quad$ - Thiamine
Vitamin $B_2 \quad-$ Riboflavin
Vitamin $B_3 \quad-$ Niacin
Vitamin $B_3 \quad$ - Pantothenic acid
Vitamin $B_6 \quad-$ Pyridoxine
Vitamin $B_{7} \quad-$ Biotin
Vitamin $B_9 \quad$ - Folic Acid
vitamin $B_{12} \quad-$ Cyanocobalomin