Iron metabolism and vitamin A deficiency in children in northeast Thailand

Abstract

To investigate the association between vitamin A and iron metabolism, two studies were carried out: a cross-sectional study and an intervention trial. The cross-sectional analysis was carried out in 1060 children aged 1-8 y. Multiple-regression analysis was used to adjust for effects of age, gender, indices of the protein nutritional status, and infections. Retinol was significantly associated with hematocrit, serum Fe, transferrin, ferritin, and saturation of transferrin (%ST). To obtain further evidence as to whether this observed association is a causal one, an intervention trial was carried out. After collection of the baseline data of 300 children, 166 children with a hemoglobin concentration less than 7.5 mmol/L were selected. A random sub-sample of 78 children received vitamin A capsules; the other children served as control subjects. Two months after supplementation significant differences, adjusted for age, were found for retinol, retinol-binding protein, serum Fe, and %ST between the supplemented and the control group. After 4 mo none of the indices were found to be significantly different between the supplemented and the control group. Periodic massive doses of vitamin A may play a role in improving the Fe status as well.

Low anemia prevalence in school-aged children in Bangalore, South India: possible effect of school health initiatives

“…Vitamin A status has been shown to be poor in school-aged children in other Indian studies (Dwivedi et al, 1992;Kapil et al, 1996;Khandait et al, 1999). Nutritional surveys have shown a close association between vitamin A deficiency and anemia (Mejia and Chew, 1988;Bloem et al, 1989). Vitamin A repletion may reduce anemia by improving utilization of stored Fe for erythropoiesis (Zimmermann et al, 2006), and by enhancing immunity and reducing the anemia of infection (Semba and Bloem, 2002).…”

The anemia of vitamin A deficiency: epidemiology and pathogenesis

“…In northeast Thailand, children who received high dose vitamin A, 60 mg retinol equivalent (RE), had higher serum iron and percentage transferrin saturation compared with control children at 2 months post-supplementation, but these differences disappeared by 4 months post-supplementation (Bloem et al, 1989). Further investigation involving school children with conjunctival xerosis showed that children who received 60 mg RE vitamin A had a significant increase in hemoglobin, hematocrit, serum iron and percentage transferrin saturation at 2 weeks following supplementation, whereas no changes of these indicators occurred in the control group (Bloem et al, 1990).…”

“…Poor vitamin A status has been associated with low iron binding capacity and percent transferrin saturation (Mejia & Anemia of vitamin A deficiency RD Semba and MW Bloem Arroyave, 1983;Bloem et al, 1989), but not low circulating transferrin concentrations (Mejia & Arroyave, 1983). Iron metabolism was examined in a large study of preschool children, age 1 -5 y, before and after a program of vitamin A-fortified sugar (Mejia & Arroyave, 1982).…”

Increase in serum beta-carotene following dark green leafy vegetable supplementation in Mebendazole-treated school children in Bangladesh

“…The assignment to the three food groups was done randomly after strati®cation for anemia, since studies have shown that vitamin A status is positively correlated with haemoglobin (Hb) levels (Ahmed et al, 1993(Ahmed et al, , 1996Bloem et al, 1989). All 164 children were given a single supervised 500 mg dose of Mebendazole 2 weeks before initiation of the supplementation trial.…”