Animal sources of iron are absorbed 2-3x more by the body than plant sources.
Good animal sources include lean beef, oysters and poultry.
The best plant sources are beans and lentils, tofu and dark green leafy veggies like spinach or kale.
Adding a Vitamin C source can enhance the absorption of iron from plant sources. These pairings can work well:
bell peppers and beans in a salad
spinach salad with lemon juice vinaigrette
fortified grains with berries
Iron can also be absorbed into your food if you cook in cast iron cookware.