<prompt> The Iron requirement in pregnant and non-pregnant women respectively:40-50mg; 20-25mg20-25mg; 15-20mg15-20mg; 40-50mg10-15mg; 15-20mg  <response>: 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 proteinsenzymes 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 mgdayMenstruating woman - 18 mgdayPregnant and lactating woman - 40 mgdayKey Concept:Iron requirement for pregnant woman is around 40mgday and in menstruating woman is around 18mgdayRef : Textbook of Biochemistry, Satyanarayana 