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

Rani, Varsha; Moretti, Diego; Khetarpaul, Neelam; Thankachan, Prashanth; Zimmermann, Michael B.; Melse-Boonstra, Alida; and Brouwer, Inge D. 2024. 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. Journal of Nutrition 154(12): 3740-3748. https://doi.org/10.1016/j.tjnut.2024.10.042

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.

Objectives 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-mo randomized, controlled trial with 6- to 10-y-old school children (n = 200; 46% anemic, 71% iron-deficient) from a rural community in Haryana, North India. Children were assigned to 2 treatment groups to daily receive either a meal of mungbean dal only (3.0 mg iron; vitamin C:iron molar ratio ∼0.5:1), or mungbean dal with fresh guava (3.2 mg iron; ∼170 mg vitamin C; molar ratio ∼18:1). Meals were served every school day under supervision. The primary outcome was body iron stores, whereas 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% confidence interval (CI): −0.34, 1.63; P = 0.197]. However, compared with 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.