Serum cobalamin concentration in tuberculosis. A study in the Guinea savanna of Nigeria

The concentration of serum cobalamin (SB12) was estimated in tuberculous Nigerian patients so as to define the role of this vitamin in the pathogenesis of the anaemia of tuberculosis. Complete data in 147 infected subjects before and during treatment and in 50 asymptomatic blood donors revealed no significant difference between mean serum cobalamin (mean SB12) concentrations of patients of both sexes and the asymptomatic controls. No differences were demonstrated between mean SB12 of groups of patients subdivided on the basis of degree of anaemia. Moreover, there was no significant correlation between Hb and SB12. Mean SB12 was essentially similar in patients with localised (300.7 pmol/l) and disseminated (311.1 pmol/l) disease. In the 121 patients with pulmonary tuberculosis, mean SB12 of those with one affected lung (291.9 pmol/l) was not significantly different from those with infection of both lungs (303.5 pmol/l). Antituberculosis therapy did not cause a fall in mean SB12. This study does not provide evidence of any significant abnormality in serum cobalamin concentration in Nigerians suffering from localised or disseminated tuberculosis. There is, therefore, no rational basis for the widespread but costineffective practice of supportive oral or parenteral vitamin B12 therapy in the management of this disease.