Vitamin D deficiency in patients with tuberculosis: prevalence, risk factors and treatment outcomes

Although vitamin D deficiency is common in tuberculosis (TB) patients, several studies demonstrated that it may not influence treatment response. The aim of this study was to evaluate the prevalence and risk factors of vitamin D deficiency in a group of TB patients and to assess whether vitamin D deficiency influences TB treatment outcomes. All patients ≥18 years of age undergoing TB treatment at the Alvorada Pulmonology Department were invited to participate in the study. Blood samples were collected to check the level of vitamin D. TB treatment outcomes were collected. In total, 106 patients met the inclusion criteria and were included in the study. The mean vitamin D level was 35.1±16.4 ng/mL. The vitamin D status was classified as normal in 63 (59.4%) patients, insufficiency in 26 (24.5%), deficiency in 12 (11.3%), and severe deficiency in 5 (4.7%). The prevalence of vitamin D deficiency was 16.0%. HIV and diabetes mellitus were more frequent in groups with insufficient and deficient vitamin D compared with the group with normal vitamin D (p=0.041 and p=0.011, respectively). Cured TB case as the treatment outcome was registered less frequently in the group with deficient vitamin D (p=0.016), with confounding factors being HIV and diabetes mellitus. In conclusion, 16.0% of TB patients had vitamin D deficiency in the present study, and HIV and diabetes mellitus were factors associated with vitamin D insufficiency and deficiency. The wide variation in results between studies probably reflects regional variations, which emphasizes the need to understand the local reality. More robust studies are needed to evaluate the effect of vitamin D deficiency on treatment cure rates.