[Current status of vitamin A deficiency in preschool children in Dongguan, China and the effect of vitamin A on serum ferritin and red blood cell parameters].

Objective: To investigate the current status of vitamin A deficiency in preschool children in Dongguan, China, as well as the effect of vitamin A on serum ferritin, red blood cell, and reticulocyte parameters.
Methods: Cluster sampling was performed from April 2015 to December 2016 to select 2 085 preschool children (3-6 years old) without any disease in Dongguan. Routine blood test, reticulocyte count, serum ferritin measurement, hemoglobin electrophoresis, and vitamin A measurement were performed for all children. The associations of age and sex with vitamin A and serum ferritin concentrations were analyzed. The effect of vitamin A concentration on serum ferritin, red blood cell, and reticulocyte parameters and the effect of reduced iron storage caused by vitamin A deficiency on red blood cell parameters were evaluated.
Results: Of the 2 085 children, 140 (6.71%) had reduced iron storage, and 678 (32.52%) had vitamin A deficiency. Among the 678 children with vitamin A deficiency, 647 (95.4%) had subclinical deficiency and 31 (4.6%) had clinical deficiency. There was no significant difference in vitamin A concentration between boys and girls, however girls had a significantly higher serum ferritin concentration than boys (P<0.05). The clinical vitamin A deficiency group had a significantly higher serum ferritin concentration than the subclinical vitamin A deficiency group and the normal group (P<0.05). In cases of vitamin A deficiency, the reduced iron storage group had significant reductions in mean corpuscular volume and mean corpuscular hemoglobin than the normal iron storage group (P<0.05). Compared with the normal vitamin A group, the vitamin A deficiency group had significantly lower hemoglobin concentration, mean corpuscular hemoglobin, red blood cell count, hematocrit, absolute reticulocyte count, reticulocyte percentage, and reticulocyte hemoglobin content, as well as a significantly higher mean corpuscular volume (P<0.05).
Conclusions: Vitamin A deficiency is prevalent in preschool children in Dongguan, China, and it may adversely affect serum ferritin, red blood cell, and reticulocyte parameters.