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': 'A 52 year old female patient complains of pain in her abdomen. General examination reveals BMI 30 Kg/m2. X-ray examination reveals osteoporotic changes. Doctor suspects impaired absorption of calcium in this patient. All of the following could be the reason for this except: \nSelect and explain. \nA. Inositol hexaphosphate in cereals, B. High intake of oxalate, C. High concentrations of fatty acids in the intestinal lumen, D. Decreased iron intake', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Phytic acid (inositol hexaphosphate) in cereals binds calcium in the intestinal lumen, preventing its absorption. Other\xa0minerals, including zinc\xa0are also chelated by phytate.\nThis is mainly a problem among people who consume large amounts of\xa0unleavened\xa0whole-wheat\xa0products;\xa0yeast\xa0contains\xa0an enzyme, phytase, that dephosphorylates phytate, so rendering\xa0it inactive.\nHigh concentrations of fatty acids in the intestinal lumen, as a result of impaired fat absorption, can also reduce\xa0calcium absorption by forming insoluble calcium salts; a high intake of oxalate can sometimes cause deficiency since calcium\xa0oxalate is insoluble.\n\nReference:\xa0 HARPERS ILLUSTRATED BIOCHEMISTRY30th, Page No: 541', 'role': 'assistant'}]