No enhancing effect of vitamin A administration on iron absorption or body total iron content in preschool children from Chengdu, China.

To explore the effect of vitamin A supplements on iron metabolic homeostasis for preschoolers. This was a randomized, placebo-controlled and blinded intervention trial with 3- to 6-y old preschoolers. A total of 445 subjects were randomly divided into four groups: a vitamin A supplementation group (group 1, a single oral dose of vitamin A as retinol 200,000 IU), an iron supplement group (group 2, daily oral supplement with the elemental iron 1-2 mg/kg/d for 5 d a week, lasting for 6 mo) a combined vitamin A and iron (group 3) and administration of no vitamin A or iron as a placebo-control (group 4). A total of 387 (95, 98, 90 and 104 from groups 1, 2, 3 and 4) children completed the intervention. After intervention, serum retinol levels of children in group 1 and group 3 was markedly higher than those of children in groups 2 and 4 (p<0.05). The serum ferritin level of children in group 1 significantly decreased after intervention (p<0.05), but increased in group 2 (p<0.05). The sTfR-SF index (TFR-F) and total body iron content (BTIC) showed the same change after intervention. In group 2 and group 3, the levels of TRF-F index and BTIC had statistically increased to the same degree after intervention (p<0.05). The impact of vitamin A intervention on iron metabolic homeostasis was mainly manifested in storage and mobilization; there was no direct effect on total body iron content or iron absorption in the intestine.

Effect of simultaneous supplementation of vitamin A and iron on diarrheal and respiratory tract infection in preschool children in Chengdu City, China.

OBJECTIVE: The goal of this study was to investigate whether vitamin A combined with iron supplementation for preschool children resulted in improved changes in children's infectious morbidity. METHOD: In this randomized placebo-controlled and blinded field intervention trial, totally 445 preschoolers, ages 3 to 6 y old, were randomly selected. All children were randomly divided into four groups: vitamin A supplement-only group (group I), iron supplement-only group (group II), vitamin A and iron supplement group (group III), and no vitamin A and ferrous sulfate as placebo-control (group IV) for 6 mo. The morbidity of diarrhea and respiratory infections, were collected during supplementation. RESULTS: There was evidence of the lowest incidence rate of respiratory-related illnesses and fewest symptoms of runny nose, cough, and fever for children in group III compared with children in groups I, II and IV (P < 0.05). Moreover, despite the undistinguished incidence rate of vomiting, nausea, and stomach pain, the rate of diarrhea-related illness was significantly lower for children in group III than for those in the other three groups. CONCLUSION: The beneficial affects on infectious morbidity over 6 mo, highlight the potential of vitamin A plus an iron supplement for preschool-aged children.