Vitamin D sufficiency in young Brazilian children: associated factors and relationship with vitamin A corrected for inflammatory status.

Abstract

OBJECTIVE\nTo assess sociodemographic, nutritional and health conditions associated with vitamin D sufficiency among young Brazilian children living at different latitudes.\n\n\nDESIGN\nCross-sectional analysis with a four-level model of inflammation to correct micronutrient concentrations. Prevalence ratios (PR; 95 % CI) were estimated for factors associated with vitamin D sufficiency (≥50 nmol/l), adjusting for child s sex, age, skin colour, stunting and vitamin A+D supplementation.\n\n\nSETTING\nPrimary health-care units in four Brazilian cities located at lower (7°59 26·9016″S and 9°58 31·3864″S) and higher latitudes (16°41 12·7752″S and 30°2 4·7292″S).\n\n\nPARTICIPANTS\nIn total 468 children aged 11-15 months were included in the analysis.\n\n\nRESULTS\nOnly 31·8 % of children were vitamin D sufficient (concentration <30 nmol/l and <50 nmol/l among 32·9 and 68·2 %, respectively). Living at higher latitudes was associated with reduced prevalence of vitamin D sufficiency compared with lower latitudes (PR = 0·65; 95 % CI 0·49, 0·85). Maternal education ≥9 years positively influenced a sufficient vitamin D status in children. After correction for inflammatory status, each increase of 1 µmol/l in vitamin A concentration was associated with a 1·38-fold higher prevalence of vitamin D sufficiency (95 % CI 1·18, 1·61). Progressive decline in the prevalence of vitamin D sufficiency was associated with marginal and deficient status of vitamin A (Ptrend = 0·001).\n\n\nCONCLUSIONS\nLower latitude, higher maternal education and vitamin A concentration were positively associated with vitamin D sufficiency in young Brazilian children. These findings are relevant for planning public health strategies for improving vitamin D status starting in early infancy.