A patient presents with low serum calcium, high phosphorus and elevated PTH. Which of the following investigations is least contributory to establish a diagnosis:
Answer is A (Vitamin D levels): Vitamin D deficiency is associated with hypophosphatemia and not hyperphosphatemia Renal failure (t serum creatinine), Pseudohypoparathyroidism (J-CAMP response to PTH) and increased urinary myoglobin (crush syndrome; tissue injury) may all be associated with combination of hypocalcemia, hyperphosphatemia and elevated PTH levels
Vitamin D levels
Serum creatinine levels
Cyclic AMP response to PTH
Urine myoglobin