Abstract
BACKGROUND: Vitamin D deficiency (VDD) is highly prevalent in children in India despite abundant sunlight. Multiple behavioral and dietary factors contribute to inadequate vitamin D status. We estimated the prevalence of vitamin D deficiency and insufficiency among apparently healthy children and explored associated sociodemographic, environmental, and dietary factors. METHODS: We conducted a cross-sectional study at the Department of Pediatrics, G.G. Hospital, Jamnagar (April 2023-June 2025). Every fourth eligible child aged 9 months-12 years attending the immunization clinic or accompanying as a healthy sibling was enrolled after consent. A structured proforma captured demographics, socioeconomic status, sun exposure (duration/body surface area), sunscreen use, and dietary practices (milk, eggs, vegetarian intake). Serum 25-hydroxyvitamin D [25(OH)D] was measured by chemiluminescent immunoassay. Vitamin D status followed IAP revised cut-offs: deficient < 20 ng/mL; inadequate 20-29 ng/mL; sufficient ≥ 30 ng/mL. Associations were analyzed using Chi-square or Fisher's exact tests (p < 0.05). RESULTS: Of 277 children (mean age 5.9 ± 3.3 years; 55.6% male), 34.7% were vitamin D deficient and 43.0% inadequate; only 22.4% were sufficient. Vitamin D status showed no significant association with age category (p = 0.757), gender (p = 0.652), or religion (p = 0.971). A strong dose-response was observed for sun exposure: <1 h/day (deficient 50.0%, sufficient 13.0%), 1-2 h/day (deficient 32.7%, sufficient 21.8%), and > 2 h/day (deficient 9.1%, sufficient 72.7%) (p < 0.01). Sunscreen use was associated with higher deficiency (50.0% vs. 31.8%, p = 0.018). Regular milk intake correlated with better status (p = 0.008); moderate egg consumption (3-5 days/week) showed the most favorable profile (p < 0.01). Socioeconomic class trended toward association (p = 0.08), with the small upper-class subgroup having highest deficiency. CONCLUSIONS: Over three-quarters of children exhibited suboptimal vitamin D status. Modifiable correlates-including sun exposure duration, sunscreen use, milk intake, and moderate egg consumption-were significantly associated with 25(OH)D levels. Pragmatic strategies combining safe sun exposure guidance, dietary counseling, food fortification, and targeted supplementation are warranted.