When all the potential risk factors were added to a multivariate model, we found that significant independent risk factors for anemia were stunted status (OR 1.9, 95%CI 1.1-3.4), low CD4 count (OR 3.2, 95%CI 1.8-5.7), detectable viral load (OR 2.4, 95%CI 1.1-5.4) and vitamin A deficiency (OR 2.5, 95%CI 1.1-5.6) (Table 1). This evidence concerns the gene CD4 and anemia (phenotype).