This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Kidney Disease & Diabetic Nephropathy, Subject name: Medicine
Which of the following is not a feature of Chronic Renal Failure? 
Select and explain. 
A. Hyperparathyroidism, B. Osteomalacia, C. Hypehyroidism, D. Decreased 1, 25(OH)2 vitamin D3 level
C: Hypehyroidism
Answer: C: Hypehyroidism 
Explanation: Choice A and D In CRF vitamin D3 production is low. This leads to low serum calcium and resultant secondary hyperparathyroidism. The increased PTH will increase the resorption of bones leading to osteitis cystica fibrosa Choice B Due to hyperphosphatemia, the increased phosphate chelates with calcium- | incidence of calcification of coronary aeries, hea valves and hence the less availability of calcium can explain the osteomalacia.