Setting: Data on vitamin D deficiency in tuberculous meningitis (TBM) and its relationship with treatment outcomes are limited. Some of the beneficial effects of vitamin D might be mediated through interleukin-1β (IL-1β).
Objective: To assess the frequency of vitamin D deficiency among TBM patients, its association with treatment outcomes and correlation between vitamin D and IL-1β levels in cerebrospinal fluid (CSF).
Design: We prospectively studied a consecutive sample of human immunodeficiency virus-negative patients with TBM treated at a hospital in southern India. We defined good outcome as survival without severe neurological disability. Serum total 25-hydroxy vitamin D (25[OH]D) and IL-1β levels in CSF were estimated on pretreatment samples.
Results: We studied 40 patients with TBM; 22 (55%) patients had stage 3 disease. Treatment outcome was poor in 21 (53%) patients: 15 (38%) patients died and 6 (15%) had severe neurological disability. The overall mean serum 25(OH)D level was 32.30 ± 16.38 ng/ml. Ten (25%) patients had vitamin D deficiency (<20 ng/ml), and 12 (30%) patients had vitamin D insufficiency (20-30 ng/ml). However, pretreatment serum 25(OH)D levels did not differ significantly by outcome (good vs. poor outcome: 28.30 ± 14.96 vs. 35.92 ± 17.11 ng/ml, P = 0.141). Moreover, IL-1β levels in CSF did not correlate with serum 25(OH)D levels (Spearman's ρ 0.083, P = 0.609).
Conclusion: Vitamin D deficiency/insufficiency is common among patients with TBM. However, serum 25(OH)D levels are not associated with IL-1β levels in CSF or treatment outcome.