As per study published by the National Library of Medicine, titled Effect of cooking food in iron-containing cookware on increase in blood hemoglobin level and iron content of the food: A systematic review, “It can be inferred that cooking food in iron pot escalates the levels of blood hemoglobin and iron content of the food, and thus reduces the incidences of iron deficiency anemia. The bioavailability of food containing heme iron increases more when cooked in iron pot than food having non-heme iron form. Also, the content of iron in the food was found to be increased by cooking acidic food with iron ingots.”

Another study titled, Beneficial effect of iron pot cooking on iron status states, when four iron rich snacks (mean iron content 2.1mg/serving) were cooked in iron pots and 27 preschool children (mean age 2.9 ± 0.9 y, 12 boys) and were supplemented with the snacks for 4 months and anthropometry and dietary intake data were collected, hemoglobin, serum iron and transferrin saturation were assessed.

And in result, there was an increase of 16.2 % in the iron content was found in the snacks cooked in iron pots than cooked in Teflon coated non-stick pots. After 4 months of supplementation, a significant increase of 7.9 % was seen in the hemoglobin of the children.