Snapshot A 6-year-old boy is brought to his pediatrician by his parents due to poor growth, weakness, and abnormal gait. On physical exam, there is bowing of the legs and tenderness upon palpation of the lower extremity. Laboratory testing is significant for a decreased serum calcium and phosphate levels and elevated parathyroid hormone and serum alkaline phosphatase levels. (Rickets secondary to vitamin D defiency) Introduction Clinical definition login to view 4 more bullets Epidemiology Demographics login to view 2 more bullets Risk factors login to view 8 more bullets Etiology Vitamin D deficiency Hypophosphatemia Chronic kidney disease login to view 1 more bullet Renal tubular acidosis login to view 2 more bullets Inhibitors of bone mineralization login to view 1 more bullet Hypophosphatasia login to view 2 more bullets Pathogenesis login to view 1 more bullet Presentation Symptoms login to view 4 more bullets Physical exam login to view 10 more bullets Imaging Radiography login to view 16 more bullets Studies Labs login to view 2 more bullets Laboratory Abnormalities in Rickets/OsteomalaciaEtiologySerum PhosphateSerum CalciumSerum Alkaline PhosphataseParathydroid HormoneVitamin D deficiency Decreased or normal Decreased or normal Elevated ElevatedUrinary phosphate wasting Decreased Normal Elevated or normal NormalProximal (type II) renal tubular acidosis Decreased Normal Normal NormalHypophosphatasia Normal Normal Decreased Normal Differential Child abuse Osteogenesis imperfecta Osteoporosis Paget disease of bone Multiple myeloma Vitamin D resistant rickets login to view 1 more bullet Laboratory Abnormalities in Select Bone DisordersEtiologySerum PhosphateSerum CalciumSerum Alkaline PhosphataseParathyroid HormoneOsteoporosisNormalNormal or decreasedNormalNormalPaget disease of the boneNormalNormalElevatedNormalOsteitis fibrosa cysticaPrimaryhyperparathyroidism •decreasedSecondaryhyperparathyroidism •increasedPrimaryhyperparathyroidism •increasedSecondaryhyperparathyroidism •decreasedPrimary and secondary hyperparathyroidism •increasedPrimary and secondary hyperparathyroidism •increasedHypervitaminosis DIncreasedIncreasedNormalDecreased Treatment Medical login to view 6 more bullets Complications Fractures Growth abnormalities Prognosis Depends on the etiology