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: Surgery
[{'content': 'Proper evaluation of serum calcium level requires estimation of: \nSelect and explain. \nA. Serum potassium, B. Serum phosphorus, C. Serum albumin, D. Urinary output', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Concentration of serum protein especially serum albumin is an impoant determinant of calcium ion concentration. Calcium is mostly bound to serum albumin. % of protein bound calcium = 0.8 x albumin (g/l) + 0.2 x globulin (gll) + 3. This formula is used for calculation of calcium bound to proteins. A rough formula is to add 1 mg/dl, to the serum calcium level for every l g/dl, by which serum albumin level is below 4 g/dL.', 'role': 'assistant'}]