Anemia was defined according to CDC recommendations as hemoglobin concentrations <110 g/L at sea level (18). Hemoglobin concentrations were adjusted for altitude following the equation proposed by Cohen and Haas (22). Iron deficiency was defined as SF <12 ug/L and as sTfR > 6 mg/L. SF indicates the level of storage iron and sTfR reflects tissue iron deficiency. Zinc deficiency was defined as by the IZnCG (<65ug/dL).