Pharmacotherapeutic Group: Ascorbic acid (Vitamin C), combinations. ATC code: А11GB.
Pharmacology: Pharmacodynamics: Ascorbic acid: Ascorbic acid (vitamin C) as antioxidant, metabolic and redox processes regulating agent, increases adaptive capacity of organism, enhances its resistance to infections. It maintains colloidal condition of intercellular substance and normal capillary penetration (it inhibits hyaluronidase). It participates in regulation of redox processes, in metabolism of carbohydrates, aromatic amino acid, pigments and cholesterol; in synthesis of steroid hormones, catecholamine, and in blood coagulation. It enhances collagen synthesis, stimulates regeneration processes, and normalizes capillary penetration. Due to activation of respiratory ferments in liver it enhances its detoxification and protein building functions; it enhances synthesis of collagen and prothrombin. It improves bile excretion, renews exocrine function of pancreas. It inhibits excretion and accelerates histamine degradation, inhibits formation of prostaglandins and other inflammatory and anaphylactic mediators. It regulates immunological reactions (it activates synthesis of antibody, C3-component of complement, interferon), facilitates phagocytosis, elevates body resistance to infections. It has an anti-inflammatory and anti-allergic action.
Daily maintenance dose of ascorbic acid in adults is 70-100 mg, in pregnant women and during lactation is 100-120 mg, in children and adolescents is 30-70 mg. Vitamin C deficient meal causes development of Vitamin C hypo or avitaminosis as this vitamin is not synthesized in organism.
Zinc: Zinc is a structural component of biological membranes, cell receptors, proteins; it takes part in more than 200 enzymatic reactions. It takes part in reactions of immune and anti-oxidant process, blood formation, amino acids synthesis, in genetic preservation and transmission. Being a component of protein, which transmits retinol, zinc together with vitamin A and vitamin C prevents immune deficit conditions, stimulates antibody synthesis and has antiviral action. It is necessary for formation of erythrocyte and other blood corpuscle. Zinc normalizes lipid metabolism, provides normal function for endocrine gland, including synthesis of insulin, growth hormone, corticotropins and somatotropins. It maintains sexual and reproductive functions – it is necessary for metabolism of vitamin E, which is a precursor of sexual hormones and takes part in testosterone production; zinc is also important for normal prostate gland functioning. Daily maintenance dose of zinc is 15 mg.
Pharmacokinetics: Ascorbic acid: Ascorbic acid is actively absorbed in small intestine. Maximal plasma concentration after oral intake is reached in 4 hours. Normal endogenous plasma concentration is approximately 10-20 mcg/ml. Body store is approximately 1.5 g. About 25% of it is bound with plasma proteins, deposited in post hypophysis, adrenal gland cortex, eye epithelium, perineal cells of seminal gland, ovary, liver, brain, spleen, pancreas, lungs, kidney, intestinal wall, heart, muscle, thyroid gland. It easily penetrates into leucocyte, thrombocyte and almost into all tissues from plasma. It is bio-transformed in liver into deoxyascorbic acid, then in oxaloacetic acid and diketogulonic acid. Unchanged ascorbate and metabolites are excreted through kidney, intestine and also with sweat and breast milk. Vitamin C absorption can be impaired in gastro-intestinal tract diseases (gastritis, ulcer, constipation, diarrhea, helminthiasis, lambliasis), usage of fresh fruit and vegetable juice, alkaline drinks. Excretion is increased if its concentration in plasma exceeds 1.4 mg/100 ml. Smoking and ethyl alcohol abuse accelerates ascorbic acid decay (transformation into inactive metabolites), sharply decreasing its reserve in body.
Zinc: Absorbed in intestine, zinc is distributed to tissues and becomes part of enzymes and biologically active substances. 90% of zinc is excreted with faeces and 2-10% with urine. Addition of calcium and calcium rich products (dairy products) reduces zinc absorption nearly by 50% and caffeine and alcohol intensively removes it from the body.