Prevalence of Vitamin B₁₂ and Folate Deficiencies in Indian Children and Adolescents

Deficiencies of vitamin B₁₂ (B₁₂) and folate (FA) are of particular interest due to their pleiotropic role in 1-carbon metabolism. In addition to adverse birth outcomes, deficiencies of B₁₂ and FA, or an imbalance in FA/B₁₂ status, are linked to metabolic disorders. Indian diets that are predominantly plant food-based could be deficient in these vitamins, but there are no national estimates of the prevalence of B₁₂ and FA deficiency in Indian children and adolescents, nor their associations with age, sex and growth indicators. The recent Comprehensive National Nutrition Survey (CNNS-2016-18) provided estimates of the prevalence of B₁₂ and FA deficiency at the national and state levels among preschool (1-4 years: 9976 and 11,004 children, respectively), school-age children (5-9 years: 12,156 and 14,125) and adolescents (10-19 years: 11,748 and 13,621). Serum B₁₂ and erythrocyte FA were measured by the direct chemiluminescence method and their deficiency was defined using WHO cut-offs. The prevalence of B₁₂ and FA deficiency was high among adolescents (31.0%, CI: 28.7-33.5 and 35.6%, CI: 33.1-8.2) compared to school-age (17.3%, CI: 15.4-19.3 and 27.6%, CI: 25.5-29.9) and preschool children (13.8%, CI: 11.7-16.2 and 22.8%, CI: 20.5-25.2, respectively). The prevalence of both B₁₂ and FA deficiency was significantly higher by 8% and 5%, respectively, in adolescent boys compared to girls. There was no association between anthropometric undernutrition and B₁₂ and FA deficiency. There was wide regional variation in the prevalence of B₁₂ and FA deficiency, but no rural-urban differences were observed across all age groups. The national prevalence of B₁₂ deficiency among preschool or school-age children was <20% (the cut-off that indicates a public health problem). However, FA deficiency in these age groups and both FA and B₁₂ deficiencies in adolescents were >20%, warranting further investigation.