Effect of biscuits fortified with different doses of vitamin A on indices of vitamin A status, haemoglobin and physical growth levels of pre-school children in Chongqing

Objective: To investigate the efficacy of biscuits fortified with different doses of vitamin A on improving vitamin A deficiency (VAD), anaemia and physical growth of pre-school children. Design: A randomised double-masked population-based field interventional trial with a positive control group. Setting: Banan district of Chongqing, China. Subjects: A total of 580 pre-school children aged 3-6 years were randomly recruited into four groups. Children in groups I and II were given biscuits fortified with vitamin A at 30 % of the recommended daily intake (RDA) and 100% of the RDA once a day for 9 and 3 months, respectively. Children in group III received biscuits containing 20 000 IU of vitamin A once a week for 3 months. Initially, the children in group IV received a 200 000 IU vitamin A capsule just once. At the beginning and end of the study, blood samples were collected to measure Hb, serum retinol, retinol-binding protein and prealbumin, and weight and height were measured. Results: All the fortification types significantly decreased the prevalence of VAD and anaemia in each group (P<0.05). The effect of 9-month intervention on group I was the most efficient (P<0.0045). After intervention, the Z-scores of height-for-age, weight-for-age and weight-for-height in all groups increased markedly compared with baseline (P<0.05), but no significant difference was observed among the groups. Conclusions: Data indicated that consuming vitamin A-fortified biscuits with daily 100% RDA for 3 months has the same effect on the improvement of VAD, anaemia and physical growth as did the weekly 20 000 IU and single 200 000 IU administration in pre-school children.