Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders


Hypophosphatemia is plasma phosphorus concentration below the normal range (~0.8-1.45mmol/L or 2.4-4.5mg/dL). The low serum concentration reflects a deficit in body phosphorus content and is accompanied by bone mineral loss.

Clinical Findings

As a result of persistent hypophosphatemia, rickets develop predominantly in children and osteomalacia in adults. Further symptoms are short stature and leg deformities.


Hypophosphatemia can be caused by an acute shift of extracellular phosphate into the cell, decreased intestinal absorption, and increased urinary excretion. Internal redistribution can be induced by increased insulin secretion, particularly during refeeding and glucose or fructose infusion, acute respiratory alkalosis, and hungry bone syndrome. Intestinal net absorption is disturbed when antacids containing aluminium or magnesium are administered, in short bowel syndrome, low dietary intake, and vitamin D deficiency or resistance. Renal excretion may be increased for acquired or genetic reasons. The acquired forms are due to hyperparathyroidism, vitamin D deficiency, oncogenic factors, osmotic diuresis, and fluid overload. Primary, genetic reasons for increased renal phosphate excretion include x-chromosomal and autosomal dominant hypophosphatemic rickets, vitamin D resistance, and Fanconi syndrome (i.e. Dent disease).


G a1 Oral intake 1400mg/d b1 Bone b0 Bowel a1->b0 a6 Bone resorption 210mg/d b1->a6 a0 Extracellular fluid plasma concentration 0,8-1,44 mmol/l a5 Bone building 210mg/d a5->b1 a6->a0 a4 Enteral secretion 210mg/d a4->b0 a7 Renal  filtration 6000-7000mg/d b2 Kidney a7->b2 a0->a5 a0->a4 a0->a7 a3 Enteral resorption 1120mg/d b0->a3 a2 Enteral excretion 490mg/d b0->a2 a8 Renal reabsorption 4800-6300mg/d b2->a8 a9 Renal excretion 1,4-1400mg/d b2->a9 a3->a0 a8->a0
Phosphat metabolism


In adults, the normal range of serum phosphate concentration is between 0.84-1.45mmol/l (2.6-4.5mg/dl). Hypophosphatemia is usually asymptomatic if not below 0.64mmol/l (2mg/dl). A severe hypophosphatemia occurs when serum concentration drops below 0.32mmol/l (1mg/dl). It becomes life threatening at 0,16mmol/l (0,5mg/dl).


Gitelman syndrome
Nephrolithiasis/osteoporosis, hypophosphatemic, 1
Hyperphosphaturia results in osteoporosis and nephrocalcinossis.
Hypophosphatemic rickets with hyperparathyroidism
Hypophosphatemia is caused by renal phosphate wastage.
Osteoglophonic dysplasia
Hypophosphatemia results from hyperphosphaturia.
Raine syndrome
In Raine syndrome hypophosphatemia is associated with sclerotic bone disease.
Update: May 11, 2019