The effect of calcium on mealworm iron metabolism

Calcium is an inhibitor of iron absorption in the mammalian iron metabolism system. The insect iron metabolism system differs from the mammalian iron system. Therefore, inhibition of iron absorption may not occur in insects as in mammals. Supplementation of iron or calcium has been studied in some insect species, as it is a potential solution to nutrient deficiencies. However, simultaneous calcium and iron supplementation has not been studied in insects. We sought to show whether calcium inhibits iron absorption in mealworms, a common edible insect, by supplementing iron and calcium jointly and measuring iron content through spectrophotometry. Based on genetic homologs between the insect and iron mammalian system, we hypothesized that calcium inhibits iron absorption in insects. Our data did not show significant differences in iron content between non-supplemented mealworms, iron-supplemented mealworms, and calcium- and iron-supplemented mealworms. However, patterns of iron content decrease and significantly less weight gain in the jointly iron- and calcium-supplemented mealworms indicate a possibility of absorption inhibition. This offers insight into the variable effects of calcium on insect metabolism. There is a need for further study of insect iron absorption inhibition to quantify calcium supplementation’s potential effects on nutrient-rich edible insect development.