There are two kinds of dietary iron -- heme iron , which comes from the hemoglobin protein in the red blood cells of animals , and non-heme iron , which comes from plants .
膳食中的铁有两种类型血红素铁，来自哺乳动物的红色血液中的血红蛋白，以及非血红素铁，来源于植物。
Excellent sources of heme iron ( 3.5 mg or more per serving ) include : liver , which has approximately 11 mg per serving depending on the type of liver ; kidney , which has 7 to 11 mg , depending on the type ; and shellfish , such as clams and oysters .
