Table 1.

Vitamin reactivity and stability in CCM: An overview of the conditions and CCM components that cause vitamin degradation and viable stabilization strategies

Vitamins	Conditions that degrade the vitamin	Compounds in CCM that enhance degradation of the vitamin	CCM components destroyed by the vitamin	Viable stabilization strategies
Riboflavin (B2)	Light, oxygen, strong alkali, divalent anions	Metal cations, thiamine HCl	AAs with heteroatoms in the side chain (e.g., Cys, Trp, Tyr), folic acid, cyanocobalamin, thiamine HCl	Avoid light or filtering out most damaging wavelengths, complexing agents, encapsulation
Folic acid (B9)	Light + oxygen, acid	Riboflavin, ascorbic acid, thiamine, reducing sugars	–	Additives to enhance solubility at low pH, avoiding light, antioxidants
Cyanocobalamin (B12)	Light, oxygen, strong acid or alkali	Ascorbic acid, riboflavin, nicotinamide, Cys, GSH, thiamine (following degradation)	–	Ferric salts, phosphate buffer, potassium ferrocyanide, filtering out most damaging wavelengths in the light source
Thiamine (B1)	Strong acid or alkali, light, oxygen, other oxidants	Sulfites, cystine, ketoacids, aldehydes (e.g., reducing sugars), metal cations, nicotinamide	Folic acid, riboflavin	Formation of/replacement with stable disulfide, additives to chelate metals, thiol additives, antioxidants, replacement with analog (nitrate)
Pyridoxine (B6)	Light, high temperatures	Any primary amine‐containing compounds (all AA, especially lysine) – pyridoxal only	Any primary amine‐containing compounds (all AA, especially lysine) – pyridoxal only	Choice of vitamer – avoid pyridoxal
Biotin (B7)	UV light, strong acid or alkali	–	–	Vitamin is stable
Pantothenate (B5)	Strong acid or alkali	Phosphate buffer, nicotinamide	–	Vitamin is stable
Nicotinamide (B3)	Acid/alkali conversion to vitamer (nicotinic acid)	–	Cyanocobalamin, thiamine, pantothenate	Vitamin is stable

CCM: cell culture media; GSH: glutathione.