SERUM RETINOL CONCENTRATIONS AND SCHISTOSOMA-MANSONI, INTESTINAL HELMINTHS, AND MALARIAL PARASITEMIA - A CROSS-SECTIONAL STUDY IN KENYAN PRESCHOOL AND PRIMARY-SCHOOL CHILDREN

Parasitic determinants of serum retinol concentrations were studied in 159 preschool (0.25-5.1 y) and 695 primary school (9.2-17 y) children in western Kenya. Mean serum retinol was 0.63 mu mol/L in preschool a nd 0.94 mu mol/L in primary school children; 62% and 24%, respectively , had serum retinol < 0.70 mu mol/L. Serum retinol was lower in boys t han in girls among both preschool (P = 0.04) and primary school childr en (P = 0.0001). Schistosoma mansoni, Ascaris lumbricoides, hookworm, and Trichuris trichiura egg output and malarial parasitemia were deter mined and their relation with serum retinol assessed. Among preschool children, sex, elevated serum concentrations of C-reactive protein, an d malarial parasitemia were significant predictors of serum retinol. A mong the 63 children from whom stool samples were available, none of t he helminth infections were significant predictors of serum retinol. F or primary school children, age, sex, and S. mansoni egg output were p redictors of serum retinol. Malarial parasitemia among nonimmune presc hool children may contribute to low serum retinol, whereas malarial pa rasitemia did not have any effects in semiimmune primary school childr en. In contrast, the inverse relation between S. mansoni and serum ret inol found in primary school children could be due to an effect of inf ection on serum retinol or an increased susceptibility to infection am ong children with low serum retinol. Although parasitic infections may contribute to poor vitamin A status in children, they do not explain the age and sex differences.