The Iron requirement in pregnant and non-pregnant women respectively:

The total content of iron in an adult body is 3-5 g.  About 70% of this occurs in the erythrocytes of blood as a constituent of hemoglobin.  At least 5% of body iron is present in myoglobin of muscle.  Heme is the most predominant iron-containing substance.  lt is a constituent of several proteins/enzymes (hemoproteins, hemoglobin, myoglobin, cytochromes, xanthine oxidase, catalase, tryptophan pyrrolase, peroxidase).  Certain other proteins contain non-heme iron e.g. transferrin, ferritin, hemosiderin. Dietary requirements: Adult man - 10 mg/day Menstruating woman - 18 mg/day Pregnant and lactating woman - 40 mg/day Key Concept: Iron requirement for pregnant woman is around 40mg/day and in menstruating woman is around 18mg/day Ref : Textbook of Biochemistry, Satyanarayana