1,25-dihydroxy vitamin D₃ (1,25(OH)₂D₃) is a potent immuno-modulator which induces LL-37, the active peptide of cathelicidin, and restricts the growth of Mycobacterium tuberculosis (Mtb) in human macrophages. In the present study, we investigated the effect of 1,25(OH)₂D₃ on cathelicidin antimicrobial peptide (CAMP) expression in healthy controls (HCs) and pulmonary tuberculosis (PTB) patients. Peripheral blood mononuclear cells (PBMCs) from 50 HCs and 35 PTB patients were cultured for 72 h either with Mtb alone or Mtb with 1,25(OH)₂D₃ at 10⁻⁷ M concentration. 1,25(OH)₂D₃ significantly up regulated the macrophage phagocytosis, CD14, CAMP gene expression and hCAP18 protein in HCs and PTB patients (p < 0.05). A significant positive correlation was observed between macrophage phagocytosis and CAMP gene expression in both the study groups (p < 0.05). Moreover, 1,25(OH)₂D₃ up regulated CAMP gene expression was more prominent in PTB patients without lung cavity (less severe form of disease) as compared to patients with cavitary TB (severe form of disease) (p < 0.05). The present study suggests that vitamin D may be used as an adjunct to anti-TB treatment and may be useful for a quicker recovery from less severe forms of TB disease.