Vitamin D and defensins production in infants

Abstract

Relevance: immunotropic effects of cholecalciferol are caused by vitamin-D-induced synthesis of antimicrobial peptides (AMP), in particular β-defensins. There are very few studies in pediatric clinical practice confirming the effect of vitamin D availability on AMP synthesis. Aim: analysis of the correlation between vitamin D availability and AMP production and assessment of the effect of cholecalciferol medication intake on defensin synthesis in young children. Materials and methods: 108 healthy children aged 1 month to 3 years were examined, of which 34 (31.5%) were adequately provided with vitamin D (calcidiol level over 30 ng/ml), 40 (37.0%) with insufficiency (20 to 30 ng/ml), 27 (25.0%) with vitamin D deficiency (10 to 20 ng/ml) and 7 (6.5%) with severe deficit (less than 10 ng/ml). In the presence of hypovitaminose of vitamin D the monthly course of cholecalciferol in doses of 2000-4000 IU/day was prescribed for correction, and in normal provision – prophylactic administration of 1000 IU/day. The indices of 25(ON)D, β1-and β2-defensins were determined three times. Results. On natural feeding, the rates of β1-defensin are 2.3 times (p<0.05) and β2-defensin 7.5 times (p<0.001) higher than those of children on artificial feeding. Against the background of the correction course, the level of β1-dephensin increased from 3.3 [2.24-5.85] pg/ml to 3.7 [2.25-6.32] pg/ml (p = 0.05), and β2-dephensin from 240.7 [86.77-686.64] pg/ml to 514.2 [468.19–1104.98] pg/ml (р<0.001). The treatment doses of cholecalciferol contributed to a more significant increase of β1-and β2-defensin; a direct correlation relationship (r = 0.34, p<0.05) was found between the daily dose of vitamin D and the increase of β2-defensin. Reception of the prophylactic dose of cholecalcipherol of 1000 IU/day during 6 months was accompanied by further increase of АМP production – the level of β1-defensin increased 2.4 times (р<0,001), and the level of β2-defensin – 2.5 times (р<0,001) in comparison with the initial values. Conclusions. Administration of cholecalcipherol preparations in children of early age is accompanied by an increase in the level of β-defensins – the most important factors of congenital immunity