This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'Which of the following vitamin enhances intestinal absorption of calcium? \nSelect and explain. \nA. Vitamin D, B. Vitamin K, C. Vitamin B1, D. Vitamin B2', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Vitamin Functions Deficiency Disease D Maintenance of calcium balance Enhances intestinal absorption of Ca2+ and mobilizes bone mineral Regulation of gene expression and cell differentiation Rickets = poor mineralization of bone Osteomalacia = bone demineralization Reference: Harper; 30th edition; Page no: 550', 'role': 'assistant'}]