A serum vitamin D level <25nmol/l pose high tuberculosis risk: a meta-analysis.
BACKGROUND
Low serum Vitamin D is considered to be associated with tuberculosis while the "dangerous" level was not clear. The aim of this study was to identify the association between tuberculosis and serum Vitamin D levels via synthesis of available evidence.


METHODS
A search of EMBASE, Medline, ISI Web of knowledge, and Pubmed was conducted. The number of subjects of tuberculosis and no-tuberculosis groups in four Vitamin D range. Meta-analyses were performed and presented by odds ratios (ORs) and corresponding 95% confidence intervals (CIs).


RESULTS
A total of 15 studies involving 1440 cases and 2558 controls were included. A significantly increased risk of tuberculosis was found in two ranges: ≤ 12.5 nmol/L: pooled OR = 4.556, 95% CI = 2.200-9.435; 13-25 nmol/L: pooled OR = 3.797, 95% CI = 1.935-7.405. No statistically significant risk of tuberculosis was found in the range of 26-50 nmol/L (pooled OR = 1.561, 95% CI =0.997-2.442). In range 51-75 nmol/L, no positive association was found (pooled OR =1.160, 95% CI = 0.708-1.900).


CONCLUSIONS
This study found that a serum Vitamin D level ≤ 25 nmol/L was significantly associated with an increased risk of tuberculosis while the range of 51-75 nmol/L was not. The range 26-50nmol/L posed potential high tuberculosis risk. Future large-scale, well-designed studies are needed to verify these results.
Department of Respiratory Medicine, Jinling Hospital, Southern Medical University (Guangzhou), Nanjing, China 210002.
Junli
J
Zeng
Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Guannan
G
Wu
Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Wen
W
Yang
Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Xiaoling
X
Gu
Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Wenjun
W
Liang
Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Yanwen
Y
Yao
Department of Respiratory Medicine, Jinling Hospital, Southern Medical University (Guangzhou), Nanjing, China 210002; Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China 210002.
Yong
Y
Song
D016022:Case-Control Studies; D006801:Humans; D016017:Odds Ratio; D012306:Risk; D014376:Tuberculosis / Q000097:blood* / Q000453:epidemiology*; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood
D014807:Vitamin D