Clinical and laboratory data to define conditions of apparent health, localised infection or inapparent infection were available for 74 anaemic Guatemalan preschool children in the baseline phase of a clinical trial of the effect of iron and vitamin A on haematological status to be correlated with serum levels of four circulating micronutrients–iron, zinc, copper and retinol–known to be influenced by activation of the acute-phase reaction. Upon enrolment, only 29.7% of the children were free of all evidence of infection, 36.5% had one or more localised conditions detected on clinical examination, and 33.8% had an elevated white cell count and/or sedimentation rate, without localising features. These were classified as‘inapparent infections’. With respect to the healthy children, levels of iron, zinc, and retinol declined and copper generally increased in the four categories of clinical infections (acute respiratory infection, dermal infections, conjunctivitis, and‘other’) but were also displaced in inapparent infections. Some activation of the acute-phase response in anaemic children may occur in the absence of clinical findings. Care must be taken in interpreting circulating micronutrient levels in relation to nutritional status in such population.