Found in: United Kingdom
Ascorbic acid, coupled with dehydroascorbic acid to which it is reversibly oxidised, has a variety of functions in cellular oxidation processes. Ascorbic acid is required in several important hydroxylations, including the conversion of proline to hydroxyproline and appears to have an important role in metal ion metabolism, including the gastrointestinal absorption of iron and its transport between plasma and storage organs.
Vitamin D2 (ergocalciferol) is a fat soluble vitamin. In conjunction with parathyroid hormone and calcitonin, it regulates calcium haemostasis. Ergocalciferol metabolites promote active absorption of calcium and phosphorous by the small intestine, increase rate of excretion and resorption of minerals in bone and promote resorption of minerals in bone and promote resorption of phosphate by renal tubules.
Pyridoxine hydrochloride is Vitamin B6. It is converted to pyridoxal phosphate which is the co-enzyme for a variety of metabolic transformations. It is essential for human nutrition.
Riboflavine is phosphorylated to flavine mononucleotide and flavine adenine dinucleotide which act as co-enzymes in the respiratory chain and in oxidative phosphorylation. Riboflavine deficiency presents with ocular symptoms, as well as lesions on the lips and at angles of the mouth.
Thiamine pyrophosphate (TPP), the coenzymatic form of thiamine, is involved in two main types of metabolic reactions: decarboxylation of α-ketoacids (e.g. pyruvate, α-ketoglutarate and branched-chain keto acids) and transketolation (e.g. among hexose and pentose phosphates). Therefore, the principal physiological role of thiamine is as a coenzyme in carbohydrate metabolism, where TPP is required for several stages in the breakdown of glucose to provide energy.
Vitamin A plays an important role in the visual process. It is isomerised to the 11-cis isomer and subsequently bound to the opsin to form the photoreceptor for vision under subdued light. Vitamin A also participates in the formation and maintenance of the integrity of epithelial tissues and mucous membranes.