Vitamin d deficiency and tuberculosis progression

Abstract

To assess the association between vitamin D deficiency and tuberculosis disease progression, we studied vitamin D levels in a cohort of tuberculosis patients and their contacts (N = 129) in Pakistan. Most (79%) persons showed deficiency. Low vitamin D levels were associated with a 5-fold increased risk for progression to tuberculosis.

Figure 1

Levels of vitamin D in plasma in the Karachi, Pakistan, tuberculosis (TB) household cohort (7) by TB status at baseline (disease-free, index TB case-patient, coprevalent TB case-patient, and past TB case-patient, treated 2–10 years previously). One disease-free contact was excluded because of an indeterminate test result. Box plots show the median, 25th, and 75th quartiles of serum vitamin D estimated for each group (A) by any TB diagnosis (current or past) at baseline (B) and by sex (C). Reference lines represent cut-offs for insufficient and sufficient vitamin D levels, respectively. The Mann-Whitney U test was used for comparison of medians.

Figure 2

Risk for tuberculosis (TB) progression, by baseline plasma vitamin D level. Risk for progression in 100 household contacts of TB patients are indicated in cohort-based tertiles of vitamin D levels in plasma at baseline: lowest, <7.4 ng/mL (red); middle, 7.4–13 ng/mL (black); highest, >13 ng/mL (blue). Plus signs indicate censoring points. Events are defined as time to diagnosis of active TB disease during follow-up.