Widespread Hypovitaminosis D among Adolescent Girls in India: The Role of Dietary Vitamin D Intake and Socioeconomic Status

Vitamin D deficiency remains a major public health concern among adolescents, particularly in low- and middle-income countries. This study assessed vitamin D status and examined socioeconomic, dietary, and lifestyle factors associated with vitamin D deficiency among adolescent girls in India. A cross-sectional study was conducted among 1009 girls aged 11–18 years attending government schools. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured to determine vitamin D status, and information on dietary intake, socioeconomic characteristics, anthropometric indicators, clinical symptoms, and lifestyle factors was collected using standardized procedures. Vitamin D deficiency (<20 ng/mL) was identified in 50.0% of participants, while 37.9% were classified as insufficient (20–29 ng/mL), 11.0% as sufficient (30–100 ng/mL), and 1.1% as having concentrations above 100 ng/mL. A substantial proportion of participants reported dietary intakes below recommended levels for energy, protein, fat, calcium, and vitamin D. Multivariable logistic regression analyses indicated that lower socioeconomic status and inadequate dietary vitamin D intake were independently associated with an increased likelihood of vitamin D deficiency. Other dietary, clinical, and lifestyle factors showed weaker or non-significant associations after adjustment for potential confounders. These findings indicate that hypovitaminosis D is highly prevalent among adolescent girls in India and highlight the important contribution of modifiable dietary and socioeconomic factors to vitamin D status. Strategies aimed at improving dietary vitamin D intake and addressing nutritional inequalities may contribute to reducing the burden of vitamin D deficiency in this vulnerable population.