Vitamin C-rich guava consumed with mungbean dal reduces anemia and increases hemoglobin but not iron stores: a randomized controlled trial of food-to-food fortification in Indian children.

BACKGROUND: Adding vitamin C-rich fruit to staples containing iron could be an effective strategy to improve iron bioavailability and thereby reduce iron-deficiency anemia in children. OBJECTIVE: We aimed to assess the effect of consuming a mungbean-based meal with or without guava fruit on body iron stores, hemoglobin concentration, and anemia of children as part of a school feeding program. METHODS: We conducted a 7-month randomized, controlled trial with 6 to 10-year-old school children (n=200; 46% anemic, 71% iron-deficient) from a rural community in Haryana, North India. Children were assigned to two treatment groups to daily receive either a meal of mungbean dal only (3.0 mg of iron; vitamin C:iron molar ratio ∼0.5:1), or mungbean dal with fresh guava (3.2 mg of iron; ∼170 mg of vitamin C; molar ratio ∼18:1). Meals were served every school day under supervision. The primary outcome was body iron stores, while concentrations of hemoglobin and other iron indicators were secondary outcomes. RESULTS: Daily consumption of mungbean dal along with guava did not result in an overall improvement of body iron stores (mean treatment effect: 0.65 mg/kg body weight; 95% CI: -0.34, 1.63; P=0.197). However, compared to children who consumed mungbean dal only, children in the guava group showed a larger increase in hemoglobin concentration (3.7 g/L; 95% CI: 1.6, 5.6; P=0.001), and a larger drop in the prevalence of anemia (-51%; 95% CIs: -74, -10; P= 0.022) and iron-deficiency anemia (-56%, 95% CI: -83, 13; P=0.087). These effects were more pronounced in children who were iron-deficient at study start. CONCLUSIONS: Addition of guava to a mungbean-based meal containing a moderate amount of iron increased hemoglobin and reduced anemia but did not provide enough additional absorbed iron to also increase body iron stores. Food-to-food fortification by inclusion of vitamin C rich fruits in iron-containing school meals may help alleviate the burden of anemia in children. This trial was registered at https://clinicaltrials.gov/ct2/show/NCT01191463.