[Fat-soluble vitamins and immunodeficiency: mechanisms of influence and opportunities for use].

The role of vitamins in the formation of the immune response, both innate and acquired immunity, is well known. At the same time, deficit of fat-soluble vitamins A, E, D leads to impaired response of the immune system to the infectious invasion and to disorders of immune system functioning. The aim of this article is to analyze the literature data on the impact of fat-soluble vitamins on the function of the human immune system and the possibilities of their use in patients with immunodeficiency. Results. Сurrently, there are enough evidences of the successful use of fat-soluble vitamins in secondary immunodeficiencies. Data on the usage of vitamins A, E, D in the treatment of primary immunodeficiencies are few. However, even reducing of antibiotics and other medicines administration in children with primary immunodeficiency indicates the feasibility of their using. The results of scientific studies on the successful use of vitamins D and A in the treatment of allergic diseases, vitamin D in the prevention and improvement of the treatment of autoimmune and oncological diseases indicate the possibility of their use as adjuvant immunomodulatory therapy in children with primary immunodeficiency. Promising may be the use of vitamins A and E, as powerful antioxidants in patients with primary immunodeficiencies with defects in DNA repair processes. Conclusion. The analysis of the literature data has shown that despite many questions need to be resolved, fat-soluble vitamins A, D, and E, and their analogues can be used in clinical settings to enhance the therapeutic effect in children with immune deficiency.

Stability of antioxidant vitamins in commercial vitamin supplements

The stability of vitamins A, E, and C was determined in 12 brands of vitamin supplements over a 12-month storage period. The variations in concentrations of these vitamins across three different batches of five brands were measured. Vitamins A and E was determined by HPLC method, and vitamin C was measured by using potentiometric titration. All samples for stability studies were maintained at room temperature and protected from light. Measurements were carried out in the first semester of the expiration date and then every six months up to 12 months of storage. After this period, only one sample showed no significant decrease in vitamin A and E concentrations in relation to the concentrations measured at the beginning of the study. The concentration of vitamin C showed no significant decrease in 50% of the samples after 6 months of storage, although after 12 months, 92% had significant losses in concentration. The analysis of the different batches showed significant variations in the vitamin levels, which do not seem to be significant for inspection purposes considering the tolerance outlined in the legislation. Over-fortification of vitamin supplements during manufacture seems to be required, but the additional amount of supplementation will depend on each sample.