<prompt> A Child with increased Ca hyperphosphatemia is seen inVitamin D dependent ricketsVitamin D resistant ricketsRenal osteodystrophyHypophosphatasia  <response>: Ans. c Renal osteodystrophy. Ref. Harrison Medicine, 18thCh.44, 279, Nelson, Paediatrics, 17th223 The principal clinical consequences of hyperphosphatemia are hypocalcemia and systemic calcification. Ectopic calcification occurs in untreated, chronic renal failure with severe hypercalcemia and in vitamin D intoxication. Tumor calcinosis is rare inherited disorder in which hyperphosphatemia is associated with ectopic calcification. Vitamin D intoxication causes excessive gastrointestinal absorption of both Ca and Ph and suppression of PTH by hypercalcemia causes decrease in renal phosphorous excretion. Hyperphosphatemia in hyperthyroidism or acromegaly is also associated with hypercalcemia. 