How Your Body Absorbs Iron—and Why Not All Sources Are Equal
Iron plays a vital role in keeping the body healthy, supporting everything from oxygen transport to immune function. Yet not all iron is the same—how well the body absorbs it depends on the type and what foods it’s paired with. Understanding these differences can help people meet their daily needs more effectively.
There are two main forms of iron in food: heme and non-heme. Heme iron comes from animal products like meat and fish, while non-heme iron is found in plant-based foods such as lentils, spinach, and seeds. The body absorbs heme iron far more efficiently, taking in around 25% of it, compared to just 17% or less of non-heme iron.
To boost absorption of plant-based iron, experts suggest combining it with vitamin C. For example, adding citrus fruits to a spinach salad can help the body take in more iron. Cooking iron-rich vegetables in a cast-iron skillet also increases their iron content.
The amount of iron needed daily varies. Adult men require 8 milligrams, while adult women need 18 milligrams—rising to 27 milligrams during pregnancy. Some of the best plant cell sources include pumpkin seeds (8.8 mg per 100g), cooked spinach (6.5 mg per cup), and lentils (3.3 mg per 100g when cooked). Other good options are Swiss chard (4 mg per cooked cup), dried apricots (2 mg per half-cup), and dates (1 mg per four Medjool dates).
Without enough iron, the body struggles to produce healthy red blood cells. This can lead to fatigue, weakened immunity, and poor cognitive function.
Meeting iron needs through diet is achievable with the right food choices and preparation methods. Pairing iron-rich plants with vitamin C or using cast-iron cookware can make a noticeable difference in absorption. For those relying on plant-based diets, including foods like spinach, lentils, and pumpkin seeds helps ensure adequate intake.
