Severe vitamin D deficiency is associated with non-tuberculous mycobacterial lung disease: A case-control study

Background and objective Previous studies have found evidence of an association between tuberculosis and vitamin D deficiency (VDD). However, the association between VDD and infection caused by non-tuberculous mycobacteria (NTM) has never been studied. This study evaluated the prevalence and severity of VDD in NTM lung disease and attempted to identify predictive factors. Methods Age- and sex-matched case-control study was conducted to assess the prevalence and severity of VDD in patients with NTM lung disease. Results After adjusting for potential confounding factors, the adjusted mean serum level of 25-hydroxyvitamin D (25(OH)D) levels was lower in 104 patients with NTM lung disease (10.7 ng/mL, 95% confidence interval (CI) 4.5-16.8 ng/mL) than that of 312 controls (13.7 ng/mL, 95% CI 7.4-19.5 ng/mL) (P = 0.012). Although the prevalence of VDD defined as serum 25(OH)D level <20 ng/mL was not different, severe VDD defined as serum 25(OH)D level <10 ng/mL was more prevalent in patients (P < 0.001). In multivariate analysis, severe (but not mild) VDD was independently associated with NTM lung disease (adjusted odds ratio 3.9, 95% CI 1.9-8.5, P < 0.001). Conclusions Patients with NTM lung disease have a high prevalence of severe VDD and VDD was independently associated with NTM lung disease. Further studies are needed to examine causality. Many epidemiological studies have found evidence of an association between tuberculosis and vitamin D deficiency (VDD). However, the association between VDD and infection caused by non-tuberculous mycobacteria (NTM) has never been studied. This case-control study showed that patients with NTM lung disease have a high prevalence of severe VDD.