This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'The Iron requirement in pregnant\xa0and non-pregnant women\xa0respectively: \nSelect and explain. \nA. 40-50mg; 20-25mg, B. 20-25mg; 15-20mg, C. 15-20mg; 40-50mg, D. 10-15mg; 15-20mg', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The total content of iron in an adult body is 3-5 g.\xa0\nAbout 70% of this occurs in the erythrocytes of blood as a constituent of hemoglobin.\xa0\nAt least 5% of body iron is present in myoglobin of muscle.\xa0\nHeme is the most predominant iron-containing substance.\xa0\nlt is a constituent of several proteins/enzymes (hemoproteins, hemoglobin, myoglobin, cytochromes, xanthine oxidase, catalase, tryptophan pyrrolase, peroxidase).\xa0\nCertain other proteins contain non-heme iron e.g. transferrin, ferritin, hemosiderin.\n\nDietary requirements:\nAdult man - 10 mg/day\nMenstruating woman - 18 mg/day\nPregnant and lactating woman - 40 mg/day\nKey Concept:\nIron requirement for pregnant woman is around 40mg/day and in menstruating woman is around 18mg/day\nRef : Textbook of Biochemistry, Satyanarayana', 'role': 'assistant'}]