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: Pediatrics
[{'content': 'Macrocytic anaemia in children is produced by all except – \nSelect and explain. \nA. Thiamine deficiency, B. Orotic acideueia, C. Copper deficiency, D. Liver disease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Morphology of RBC \n\nNormal human red blood cells are biconcave discs (diskocytes) with a mean diameter of about 7.5 m.\nThe hemoglobin of red cells is located peripherally, leaving an area of central pallor equal to approximately 30-35% of the diameter of the cells. \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0\nCells of normal size and normal hemoglobin content (color) are termed normocytic and normochromic.\nWhen red cells diameter is greater than 9 mm, they are referred to as macrocytes.\nWhen red cells diameter is less than 6 mm, they are referred to as microcytes.\nVariation in size of RBCs is known as anisocytosis.\nVariation in shape of RBCs is known as poikilocytosis.\n\nCauses of macrocytosis\n\nCauses of megaloblastic anemia :\n\nVitamin B12 deficiency : \n\nDecrease intake - Inadequate diet, vegetarianism.\nImpaired absorption :\nIntrinsic factor deficiency\nPernicious anaemia\nGastrectomy\nMalabsorption states\nDiffuse intestinal disease eg Lymphoma, systemic sclerosis.\nBeal resection, ilitis\nCompetitive parasitic uptake eg. fish tape worm infestation.\nBacterial over growth in blind loops and diverticula of bowel.\nIncreased requirement: pregnancy, hyperthyroidism, disseminated cancer.\n\nFolic acid deficiency :\n\nDecreased intake : inadequate diet, alcoholism & infancy\nImpaired absorption e.g. malabsorption state\nIntestinal diseases\nAnticonvulsants, OCP.\nIncreased loss: haemodialysis\nIncreased requirement : Pregnancy, infancy, disseminated cancer & markedly increased haemoptysis.\nImpaired use : folic acid antagonist.\n\nOther causes of megaloblastic anemia\n\nThiamine deficiency \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0\xa0\nPyridoxine deficiency\xa0\nHereditary orotic aciduria\xa0\xa0\nCongenital dyserythropoietic anemia\xa0\xa0\xa0\xa0\xa0\nDi-Gueglielrno syndrome\xa0\xa0\xa0\nHypothyroidism', 'role': 'assistant'}]