Nutritional supplements for people being treated for active tuberculosis

Abstract

Background: Tuberculosis is a serious infection affecting mainly the lungs. It may contribute to nutritional deficiencies which in turn may delay recovery by depressing immune functions. Nutritional supplements might therefore promote recovery in people being treated for tuberculosis. Objectives: To assess the provision of oral nutritional supplements to promote the recovery of people being treated with antituberculous drug therapy for active tuberculosis. Search strategy: We searched the Cochrane Infectious Disease Group Specialized Register (June 2008), CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE (June 2008), EMBASE (June 2008), LILACS (June 2008), mRCT (June 2008), the Indian Journal of Tuberculosis (1983 to June 2008), and checked the reference lists of all included studies. Selection criteria: Randomized controlled trials comparing any oral nutritional supplement given for at least four weeks with no nutritional intervention, placebo, or dietary advice only for people being treated for active tuberculosis. Data collection and analysis: Two authors independently selected trials, extracted data, and assessed risk of bias. We calculated risk ratios (RR) for dichotomous variables and mean differences (MD) for continuous variables, with 95% confidence intervals (CI). We pooled data from trials with similar interventions and outcomes. Main results: Twelve trials (3393 participants) were included. Five trials had adequate allocation concealment. Interventions included a high energy supplement, high cholesterol diet, vitamin D, vitamin A, zinc, arginine, multiple micronutrient supplements, combined multiple micronutrient supplements and zinc, combined vitamin A and zinc, and combined vitamin A and selenium. The following supplements were associated with increased body weight at follow up: high energy supplements (MD 1.73 kg, 95% CI 0.81 to 2.65; 34 participants, 1 trial); multiple micronutrients plus additional zinc (MD 2.37 kg, 95% CI 2.21 to 2.53; 192 participants, 1 trial); and vitamin A plus zinc (MD 3.10 kg, 95% CI 0.74 to 5.46; 80 participants, 1 trial). There was no evidence that any supplement affected the number of deaths or number of participants with sputum test positive results at the end of treatment. Authors' conclusions: There is limited evidence that high energy supplements and some combinations of zinc with other micronutrients may help people with tuberculosis to gain weight. There is not enough evidence to assess the effect of other combinations of nutrients. A number of relevant trials are in progress, and, where appropriate, the results will be incorporated into future updates of this review. Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.