From the Guidelines
Hypophosphatemia can result from various etiologies, including inherited or acquired causes of phosphopenic rickets, such as primary renal tubular phosphate wasting, X-linked recessive hypophosphataemic rickets, and hypophosphataemia and nephrocalcinosis, as well as other factors like malnutrition, vitamin D deficiency, and certain medications. The etiologies of hypophosphatemia can be categorized into several mechanisms, including:
- Decreased intestinal absorption, which occurs with malnutrition, vitamin D deficiency, chronic diarrhea, malabsorption syndromes, and use of phosphate binders like aluminum hydroxide, calcium carbonate, or sevelamer 1
- Increased urinary excretion, which happens in hyperparathyroidism, vitamin D deficiency, renal tubular disorders (like Fanconi syndrome), diuretic use (especially loop diuretics), and post-renal transplantation 1
- Intracellular shifting of phosphate, seen during refeeding syndrome, with insulin administration in diabetic ketoacidosis treatment, respiratory alkalosis, hungry bone syndrome after parathyroidectomy, and during recovery from severe burns 1 Certain medications can also cause hypophosphatemia, including antacids, bisphosphonates, glucocorticoids, and certain chemotherapeutic agents, as well as treatment with ferric carboxymaltose (FCM) 1. Some key factors that contribute to the development of hypophosphatemia include:
- Recurrent or ongoing blood loss
- Malabsorptive disorders
- Normal renal function
- Severe iron deficiency
- Lower body weight
- Low baseline serum phosphate
- Higher serum PTH 1 It is essential to identify and address the underlying cause of hypophosphatemia to provide appropriate treatment and prevent complications.
From the Research
Etiologies of Hypophosphatemia
The etiologies of hypophosphatemia can be categorized into several main mechanisms, including:
- Decrease in digestive absorption
- Rise in kidney excretion
- Transfer of phosphorus to the intracellular compartment 2 These mechanisms can be triggered by various factors, such as:
- Denutrition
- Acid base balance troubles
- Parenteral nutrition
- Several drugs 2
- Redistribution of P to the intracellular space
- Increased renal losses
- Decreased intestinal absorption 3
Acquired and Genetic Causes
Hypophosphatemia can be due to acquired or genetic causes, with most cases being acquired 3 Acquired causes can include:
- Vitamin D deficiency 4
- Parathyroid hormone (PTH) imbalance 4
- Fibroblast growth factor 23 (FGF23) imbalance 4 Genetic causes can include:
- Phosphate-wasting diseases 5
- Disorders of phosphate regulation 6
Regulation of Phosphate Homeostasis
Phosphate homeostasis involves several major organs, including: