Aim: To conduct a systematic review and meta-analysis of all published studies studying the risk of vitamin D deficiency in tuberculosis patients and in healthy controls. Additionally, subgroup meta-analysis was performed based on the level of vitamin D to test the risk in TB groups and in healthy groups.
Methods: Pubmed was searched for observational studies in human and English that discussed the association between risk of low serum vitamin D and TB. Meta-analysis was performed on all relevant studies combined and for subgroups of each vitamin D level.
Results: 22 studies were selected and pooled in the analysis. The results were consistent with previous studies examining the same risk. The overall log risk ratio (log RR) of low vitamin D was significantly higher in TB patients 1.68 times than healthy controls. In 4 subgroup meta- analyses based on vitamin D level below (20 nmol/L, 30 nmol/L, 50 nmol/L, and 75 nmol/L), the risk of having low vitamin D in TB patients was (1.82, 2.89, 1.38, 1.32) respectively. That subgroup analysis showed more clearly the higher RR were below 20 and 30 nmol/L. The smallest RR was at 75 nmol/L level.
Conclusion: This study verified the association between risk of low vitamin D level and TB development. It also clarified that, the risk increased by decreasing vitamin D level.