Randomized efficacy trial of a micronutrient-fortified beverage in primary school children in Tanzania.

Randomized, school-based efficacy trial in rural primary-school children in Mpwapwa District, Tanzania. The active intervention arm included 392 children aged 6 to 11 years from six schools; the comparator arm received an identical unfortified beverage. Participants were Wagogo and Wakaguru children, with baseline anemia and low serum retinol common in both arms.

Children in the active intervention group received an orange-flavored fortified beverage as a 25-g sachet mixed with 250 mL of previously boiled water, taken orally 5 days per week for 6 months. The beverage provided 10 micronutrients at physiologic doses, including vitamin A as retinyl palmitate, and was compared with an identical unfortified beverage.

The fortified beverage improved hematologic status, vitamin A status, and growth compared with the unfortified beverage. Hemoglobin declined less in the fortified group than in the nonfortified group (−3.2 ± 13 vs −6.7 ± 13; between-group P = 0.001), ferritin increased more, and ferritin < 12 g/L fell to 1.3% versus 6.7% (RR 0.18; P = 0.001). Anemia at follow-up was lower with fortification (26.3% vs 35.6%; RR 0.73; P = 0.005), and vitamin A deficiency declined from 21.4% to 11.3% in the fortified group while remaining 19.7% in the nonfortified group. Weight, height, and BMI gains were also greater in the fortified group, with between-group P = 0.001 for each growth outcome.

The intervention was only 6 months long and was tested in one rural district, which limits generalizability. The beverage contained multiple micronutrients, so the specific nutrient driving each benefit cannot be isolated. Baseline and follow-up occurred in different seasons, including a period of higher malaria transmission, which could have influenced hematologic and growth outcomes.