Prevalence of Vitamin D Deficiency Among Children With Tuberculosis and Its Relationship With Demographic and Clinical Characteristics

Background Tuberculosis (TB) continues to be a significant contributor to childhood morbidity and mortality in high-burden countries, including India. Host nutritional status plays an important role in susceptibility to Mycobacterium tuberculosis, particularly through the modulation of cell-mediated immunity. Beyond its classical role in calcium homeostasis, vitamin D has important immunomodulatory effects, including enhancement of macrophage activity, promotion of phagosome-lysosome fusion, and induction of antimicrobial peptides such as cathelicidin. Although several studies in adults have reported an association between vitamin D deficiency and active TB, pediatric data, particularly from the Indian subcontinent, remain limited. The present study was conducted to determine the prevalence of vitamin D deficiency among children with TB and to examine its relationship with selected demographic and clinical characteristics. Methods This prospective study was conducted over a 12-month period and included 41 children aged ≤18 years who were newly diagnosed with TB. Sociodemographic and clinical data were collected using a structured proforma. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured using a chemiluminescence assay and expressed in nmol/L. Vitamin D status was categorized as deficient (<50 nmol/L) or non-deficient (≥50 nmol/L). The distribution of vitamin D levels was analyzed according to age group, sex, socioeconomic status, TB diagnosis category, monthly family income, and diagnostic method. Results Among the 41 children with TB, vitamin D deficiency was observed in 37 (90.2%) participants, while only 4 (9.8%) had non-deficient vitamin D levels. The mean serum vitamin D level was 34.75 ± 11.28 nmol/L. Pulmonary TB was the most common diagnosis (41.5%), followed by abdominal TB (29.3%), central nervous system (CNS) TB (19.5%), and disseminated TB (9.7%). Vitamin D deficiency was observed across all age groups and socioeconomic strata. However, no statistically significant association was found between vitamin D deficiency and age group (p = 0.524), sex (p = 0.762), socioeconomic status (p = 0.908), TB diagnosis category (p = 0.640), monthly family income (p = 0.790), or diagnostic method (p = 0.730). Pearson correlation analysis showed weak, non-significant correlations between vitamin D levels and age (r = 0.082, p = 0.610), as well as monthly family income (r = 0.088, p = 0.584). Conclusions This study demonstrated a high prevalence of vitamin D deficiency among children diagnosed with TB. While no statistically significant association was identified between vitamin D deficiency and the demographic or clinical parameters assessed, the findings highlight the frequent occurrence of inadequate vitamin D levels in pediatric TB. Larger prospective studies are needed to further clarify the role of vitamin D in childhood TB and to explore the potential therapeutic value of vitamin D supplementation.