Micronutrient supplementation can reduce the risk of recurrent TB

Nutritional assessment and support in TB therapy was common before the advent of anti-TB drugs, but it is no longer an integral part of clinical therapy in most low-income countries.

In Tanzania, Eduardo Villamor and a team of researchers conducted a randomised trial of micronutrients using doses of vitamins A, B-complex, C, E, and selenium or placebo in 887 patients receiving tuberculosis therapy. These patients were then followed for a median of 43 months; 471 were HIV-coinfected and not receiving antiretroviral therapy, and 416 were HIV-uninfected.

The study showed that micronutrient supplementation was associated with reduced rates of TB recurrence. In the study, both HIV-infected and -uninfected patients with pulmonary TB who were receiving the supplements had a decreased risk of TB recurrence in the months after the TB culture had become negative -- 45% overall and 63% in HIV-infected patients. Supplementation also reduced the incidence of peripheral neuropathy by 57% irrespective of HIV status, and increased the levels of CD3 and CD4 cells.

Villamor reported that the decrease in recurrence "was stronger in patients infected with HIV than in those who were HIV-negative. This could be relevant because TB reactivation is common among HIV-infected persons." He further noted "that it will be important to find out whether micronutrients improve the outcome of TB treatment in TB-HIV co-infected patients who are undergoing antiretroviral therapy."

Results to date relating to TB recurrence and mortality are inconsistent, with previous studies using different dosages and combinations of micronutrients. Researchers conclude that further investigations are needed to develop optimal combinations of micronutrients that can be provided inexpensively in TB therapy to reduce relapses and increase survival.