Vitamin D status and determinants in Indian children and adolescents: a multicentre study

Abstract

Studies performed on Indian children to assess vitamin-D status have been on small sample sizes, limited to specific geographical locations and used non-standard methods to measure 25(OH)D₃. This multicentre study assessed 25(OH)D₃ concentrations from dried blood spots (DBS) in 5-18-year-old Indian children and adolescents using a standardized protocol and identified factors contributing towards vitamin D deficiency. Cross-sectional, observational school-based study was conducted by multi-stage stratified random sampling. A city and nearby village were selected from 6 Indian states covering wide geographical areas. Demography, anthropometry, body-composition, dietary-intakes and DBS samples were collected. 25(OH)D₃ was assessed from DBS using Liquid chromatography with tandem-mass spectrometry. Vitamin-D status was assessed in 2500 children; with additional data collected on a subset (n = 669) to assess predictors. Mean vitamin-D concentration was 45.8 ± 23.9 nmol/L, 36.8% of subjects had sufficient vitamin-D (> 50 nmol/L); rural subjects and boys had higher concentrations (p < 0.05). On regression analysis, younger age, female-gender, overweight and urban residence significantly contributed to deficiency. More than half the Indian children/adolescents were vitamin-D deficient or insufficient. Our study reinforces vitamin-D deficiency as a major public health problem and the need for supplementation, food fortification and educating the population as initiatives required to improve sufficiency status.

Figure 1

Flow diagram of study participants.

Figure 2

State wise comparison of mean (± SE) Vitamin D concentrations stratified by urban rural residence and gender. p values are displayed in Table 1 between urban and rural counterparts.

Figure 3

Vitamin D status (proportion deficient, insufficient, sufficient) in urban rural boys and girls from 6 Indian States.

Figure 4

(a–c) Indian state wise prevalence of vitamin D-deficiency, insufficiency and sufficiency. (Created with mapchart.net (https://www.mapchart.net/india.html)).