Cast iron cookware has a great reputation in the kitchen. You can use it for a multitude of cooking techniques from browning meat and veggies to baking bread, to slow-cooking flavorful stews. Did you know, though, that anything you cook in cast iron might actually increase your daily iron intake?

“A systematic review published in 2021 found that cooking in cast iron cookware can increase blood hemoglobin levels and boost the iron content of foods,” reveals nutrition expert Maya Feller, MS, RD, CDN. “The studies included in this review found that blood hemoglobin levels—or iron markers—noticeably increased from 0.3 g/dl all the way up to 1.7 g/dl after cooking food in cast iron cookware.”

The foods that demonstrated the highest increase were meat and vegetables prepared in cast iron.

So, why is this important? Well, according to Feller, iron plays a big role in multiple functions within the body, and it’s also an essential nutrient, meaning that our bodies have to get it from external sources. “Iron is a component of hemoglobin, which carries oxygen to the muscles and it’s important for hormone production, cell functioning, and neurological development,” she adds.

How much iron do we need?

Each individual’s optimal iron intake depends on factors such as age, sex, and pregnancy status. For non-vegetarian adult men, the RDA for iron is 8 mg per day, but it’s 18 mg per day for women and 27 mg per day for pregnant women. For vegetarians, the RDA is 1.8 times higher than it is for regular meat-eaters.

All things considered, it’s also important to note that, while preparing food in cast iron cookware is beneficial in terms of contributing iron to meals, quantifying that increase precisely is difficult. “Absorption is influenced by many variables including age, the size of the pot, preparation technique, as well as the duration of cooking,” Feller explains. Her suggestions for boosting iron content are longer cooking times, frequent stirring, and maximizing food surface area contact.