An Unusual Presentation of Hypophosphatemic Rickets

ABSTRACT Objective: Availability and absorption of phosphate is crucial for bone mineralization. Hypophosphatemia can lead to defective bone mineralization and consequently, rickets. Maintenance of phosphate levels relies on dietary intake, gastrointestinal absorption, renal re-absorption, and renal excretion. We report a case of an 8-month-old girl with hypophosphatemic rickets that exhibited appropriate dietary intake of phosphate and appropriate renal re-absorption of phosphate. Methods: Case report and literature review. Results: The most widely encountered mechanism for hypophosphatemic rickets is renal phosphate wasting. In this patient, decreased gastrointestinal absorption of phosphate was the most likely etiology of hypophosphatemia. With a simple dietary maneuver, she achieved resolution of hypophosphatemia and improvement in bone mineralization. Conclusion: This case highlights the importance of considering extra-renal etiologies of hypophosphatemic rickets and careful dietary history, even in infants. Abbreviation: PTH parathyroid hormone