Revisiting the Association Between Vitamin D Deficiency and Active Tuberculosis: A Prospective Case-Control Study in Taiwan

Background: To revisit the association between vitamin D deficiency (VDD, defined as serum 25(OH)D < 20 ng/ml) and incident active tuberculosis (TB), after two potentially underpowered randomized trials showed statistically non -significant 13%-22% decrease in TB incidence in vitamin D supplementation groups. Methods: We prospectively conducted an age/sex-matched case -control study that accounting for body -mass index (BMI), smoking, and other confounding factors to examine the association between VDD and active TB among non -HIV people in Taiwan (latitude 24 degrees N), a high-income society which continues to have moderate TB burden. Results: We enrolled 62 people with incident active TB and 248 people in control group. The TB case patients had a significantly higher proportion of VDD compared to the control group (51.6% vs 29.8%, p = 0.001). The 25(OH)D level was also significantly lower in TB patients compared to control group (21.25 +/- 8.93 ng/ml vs 24.45 +/- 8.36 ng/ml, p = 0.008). In multivariable analysis, VDD (adjusted odds ratio [aOR]: 3.03, p = 0.002), lower BMI (aOR: 0.81, p < 0.001), liver cirrhosis (aOR: 8.99, p = 0.042), and smoking (aOR: 4.52, p = 0.001) were independent risk factors for incident active TB. Conclusions: VDD is an independent risk factor for incident active TB. Future randomized trials examining the effect of vitamin D supplementation on TB incidence should focus on people with a low BMI or other risk factors to maximize the statistical power. Copyright (c) 2024, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).