This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
[{'content': 'All of the following reduce T4 absorption except \nSelect and explain. \nA. Metformin, B. Iron salts, C. Raloxifen, D. Colsevelam', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer Goodman Gilman 12/e p1136 Absorption of T4 is reduced by Antacids Bile acids binding agents Calcium carbonate Iron salts Proton pump inhibitors. Raloxifen Sucralfate', 'role': 'assistant'}]