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

Abstract

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.