Randomized controlled trial of zinc and vitamin A as co-adjuvants for the treatment of pulmonary tuberculosis

Trop Med Int Health. 2010 Dec;15(12):1481-90. doi: 10.1111/j.1365-3156.2010.02638.x. Epub 2010 Oct 19.


Objective: To assess the efficacy of weekly zinc or zinc plus retinol as adjuncts for the treatment of pulmonary tuberculosis.

Methods: Double-blind, randomized, placebo-controlled trial in 350 patients >15 years old with smear-positive tuberculosis in Nigeria (ISRCTN36636609). In addition to antituberculous treatment, patients were randomly allocated to weekly supplements of zinc (90 mg), zinc plus retinol (5000 IU) or placebos for 6 months. Primary outcomes were time to sputum smear conversion and resolution of radiographic abnormalities.

Results: After 8 weeks of treatment, 68% had achieved sputum smear conversion, and the median conversion time was 6.5 weeks. Hazard ratios (HR, 95%CI) for sputum conversion relative to the placebo group were not significant for zinc (1.07, 0.92-1.29) or zinc plus retinol (0.89, 0.76-1.07). Significant predictors of time to sputum conversion were lung abnormality score, sputum smear grade, age and serum C-reactive protein. HIV co-infection and gender were not independent predictors of time to sputum conversion. There were no significant differences between supplement groups in clinical, radiological or laboratory outcomes at 2 months or 6 months. There were 9, 9 and 2 deaths in patients receiving zinc, zinc plus retinol or placebos, respectively. Mortality in those who received zinc (HR 1.71, 0.88-3.58) or zinc plus retinol (HR 1.54, 0.78-3.26) did not differ significantly from those who received placebos. Most deaths occurred in patients co-infected with HIV.

Conclusions: Supplementation with zinc or zinc plus retinol did not lead to better outcomes than placebos, and caution is warranted regarding routine micronutrient supplementation, particularly in patients co-infected with HIV.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Antitubercular Agents / therapeutic use*
  • Cough / microbiology
  • Dietary Supplements*
  • Double-Blind Method
  • Drug Administration Schedule
  • Drug Therapy, Combination
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mycobacterium tuberculosis / isolation & purification
  • Radiography
  • Sputum / microbiology
  • Treatment Outcome
  • Tuberculosis, Pulmonary / complications
  • Tuberculosis, Pulmonary / diagnostic imaging
  • Tuberculosis, Pulmonary / drug therapy*
  • Vitamin A / therapeutic use*
  • Young Adult
  • Zinc / therapeutic use*


  • Antitubercular Agents
  • Vitamin A
  • Zinc

Associated data

  • ISRCTN/ISRCTN36636609