Vitamin D Status in Children Diagnosed with Pulmonary Tuberculosis: Hospital-Based Prospective Evaluation (February–October 2025)

Background: Tuberculosis (TB) remains a significant source of childhood morbidity and mortality in nations with a high TB burden, such as India, which contributes approximately one-quarter of all TB cases worldwide. Vitamin D is a significant nutrient that helps the body fight Mycobacterium tuberculosis by affecting both innate and adaptive immunity. The association between low vitamin D levels and active TB is tested through observational studies, although limited research exists on children in India. Purpose: (1) to determine the serum level of 25-hydroxyvitamin D [25(OH)D] in children with pulmonary tuberculosis; (2) to determine the prevalence of vitamin D deficiency and insufficiency; and (3) to clarify whether there is a correlation between the level of vitamin D and the clinical/radiological severity of pulmonary TB. Material and Methods: This hospital-based prospective observational study was conducted between February 4, 2025, and October 31, 2025, at the Departments of Paediatrics and Respiratory Medicine at Al Falah Medical College and Hospital. Thirty children aged 1 to 14 years were recruited in consecutive order and were newly diagnosed with pulmonary TB according to the recommendation of the national TB program. Their demographic information, nutritional conditions, clinical presentation, contact history, and radiographic images were captured. A chemiluminescent immunoassay was used to measure serum 25(OH)D. According to the Indian Academy of Pediatrics (IAP) cut-offs, vitamin D deficiency, insufficiency, and sufficiency were defined as 20 ng/mL, respectively. The severity of diseases (mild, moderate, severe) was determined by clinical burden of symptoms, radiographic (extent), and microbiological (confirmation) aspects. Descriptive statistics were used to analyze the data, and the chi-square test and Student t-test were used; a p-value of less than 0.05 was considered significant. Results: The mean age of the participants was 8.1 3.2 years, and 16 (53.3%) were boys. The total prevalence rate of vitamin D deficiency was 18 (60%), insufficiency 7 (23.3), and only 5 (16.7) had an enough amount of vitamin D. Children under-nourished (BMI-for-age below-2 SD) were prevalent in 17 (56.7) children and more frequent in children with vitamin D deficiency than in those with adequate levels (72.2% vs 33.3%; p=0.04). The proportion of moderate-to-severe pulmonary TB was 20 (66.7%; p=.02), and it was also strongly correlated with vitamin D deficiency: 15/18 (83.3%; 5) deficient and 5/12 (41.7%; 58.3%) non-deficient children showed moderate-to-severe TB. Those with moderate-to-severe disease had lower mean serum 25(OH)D levels (11.5 4.2 ng/mL) than those with mild disease (17.0 3.8 ng/mL; p=0.002). Conclusion: Among children in this hospital-based group with TB of the pulmonary type, a high prevalence of low levels of vitamin D was demonstrated. Under-nutrition and more serious illness were strongly associated with vitamin D deficiency. The results of this study indicate that regular testing of vitamin D status should be considered as a potential additional measure in the management of pediatric pulmonary TB, with appropriate correction. It is worth noting, though, that the trials have conflicting results in clinical use. Keywords: Vitamin D, 25-hydroxyvitamin D, pulmonary tuberculosis, children, hypovitaminosis D, under-nutrition, India.