OBJECTIVE:

High prevalences of vitamin A deficiency and anaemia among adolescents warrant interventions. This study evaluated the effectiveness of school-based supplementation to reduce anaemia and improve vitamin A status.

DESIGN:

School-based, grade-randomized, intervention.

SUBJECTS AND SETTING:

In all, 1757 girls and 1859 boys, aged 12-15 y, in 24 Junior High Schools.

INTERVENTIONS:

Weekly supplementation for 14 weeks with 60 mg iron and 250 microg folate (Fe group; n=978), 10 000 IU vitamin A (VA group; n=970) or both (VAFe group; n=1042) to subjects in 15 schools, compared to subjects in nine other schools not receiving supplements (control; n=626).

RESULTS:

The baseline anaemia prevalence (Hb <120 g/l) in girls was 20% (prepubertal) and 26% (pubertal), and in boys 24% (pre-pubertal) and 11% (pubertal). Serum retinol concentrations were low (<1.05 micromol/l) in 41% of boys and 45% of girls. The interventions did not increase haemoglobin concentrations. Serum retinol concentration of boys, but not girls, in the VA group increased (0.33 vs 0.07 micromol/l in controls; P<0.01). The risk factors for low serum retinol concentration were lower baseline serum retinol concentration (OR 0.02-0.03) with, for girls, nightblindness at baseline (OR 5.88), and for boys, not receiving vitamin A (OR control: 1.00; VA: 0.37; Fe: 0.77; VAFe: 0.34) and maternal illiteracy (OR mother never attended school 1.00, mother received any formal education 0.17-0.33).

CONCLUSIONS:

Supplementation with vitamin A increased serum retinol concentration of boys. Iron supplementation did not change Hb. This appeared to be due to poor compliance, and partly related to side effects.