Iron has always struck me as the nutritional equivalent of Stanley Tucci: It's frequently popping up in unexpected places, and experts say that's a good thing. One of those mysterious minerals that can be found in lentils or a steak, iron is critical to health, but to understand exactly why it's so important and whether some sources of iron are better than others, I asked nutritional specialists.
"Iron is a mineral, and what's unique about iron and makes it so beneficial to humans is that it can actually change its [chemical] state pretty easily," says Andrew Jones, an assistant professor of nutritional sciences at the University of Michigan School of Public Health. "That allows it to have a number of different roles in the body."
Iron's most conspicuous role is as a part of hemoglobin, the protein in red blood cells that transports oxygen throughout the body. Though iron is essential to anyone trying to stay alive, the amount one needs changes over the years. Children need varying levels of iron depending on age. Men ages 19 and older should get 8 mg of iron per day, while women ages 19-50 should get 18 mg daily and then 8 mg in the years after.
"It's more common for women to be low in iron," says Vandana Sheth, a spokesperson for the Academy of Nutrition and Dietetics and a nutritionist practicing in the Los Angeles area. "Our body stores iron, but some of our storage capacity goes away every month during our menstrual cycle." A pregnant woman needs even more iron — 27 mg per day — because she must share hers with a fetus. People who aren't getting enough iron may have pale skin, feel easily tired, and develop headaches.
Not all iron is the same. There are two types: heme iron and non-heme iron. Heme iron is found in meats, especially in red meat and in organ meat like liver, which stores excess iron in humans and other animals. Non-heme iron, on the other hand, is found in beans, lentils, spinach, kale and apricots, to name a few sources. The body does not absorb non-heme iron as well as heme iron, so vegetarians may need to consume as much as double the daily amount of iron as someone who eats meat.