Vitamin B6 in its phosphorylated form (pyridoxal-5?-phosphate – PALP) is a coenzyme of a number of enzymes that interact in the general non-oxidative metabolism of amino acids. Through decarboxylation, they are involved in the formation of physiologically active amines (e.g. adrenaline, histamine, serotonin, dopamine, tyramine), through transamination – in anabolic and catabolic metabolic processes (e.g. glutamate-oxaloacetate transaminase, glutamatepyruvate transaminase, GABA, ?-ketoglutarate transaminase), as well as in various processes of amino acid breakdown and synthesis. Vitamin B6 acts on 4 different sites of tryptophan metabolism. In the process of hemoglobin synthesis, vitamin B6 catalyzes the formation of ?-amino-?-ketoadenic acid.

Vitamin B12 is necessary for cellular metabolism. It affects the function of hematopoiesis (extrinsic anti-anemic factor), participates in the formation of choline, methionine, creatinine, nucleic acids, and has an analgesic effect.

Pharmacokinetics. When administered orally, vitamin B6 and its derivatives are mostly rapidly absorbed in the upper digestive tract by passive diffusion and excreted within 2-5 hours. After parenteral administration, thiamine is distributed in the body. About 1 mg of thiamine is metabolized daily. Metabolites are excreted in the urine. Dephosphorylation occurs in the kidneys. The biological half-life of thiamine is 0.35 hours. Thiamine does not accumulate in the body due to its poor solubility in fats.

Vitamin B6 is phosphorylated and oxidized to pyridoxal-5?-phosphate. In blood plasma, pyridoxal-5?-phosphate and pyridoxal are bound to albumin. It is transported in the form of pyridoxal. To pass through the cell membrane, pyridoxal-5?-phosphate, bound to albumin, is hydrolyzed by LF to pyridoxal.

Vitamin B12 after parenteral administration forms transport protein complexes that are rapidly absorbed by the liver, bone marrow and other organs. Vitamin B12 enters the bile and participates in the enterohepatic circulation, penetrates the placental barrier.