Sorted By Test Name - Mayo Medical Laboratories

PHBF
8029
RPOU
84007
POU
8526
West J Med 1987;147: 569-576
Phosphorus, Body Fluid
Clinical Information: Not available
Useful For: Not established
Interpretation: None available
Reference Values:
Not Applicable
Clinical References: Tietz Textbook of Clinical Chemistry. Edited by Burtis and Ashwood.
Philadelphia, WB Saunders Co, 1994
Phosphorus, Pediatric, Random, Urine
Clinical Information: Approximately 80% of filter phosphorous is reabsorbed by renal proximal
tubule cells. The regulation of urinary phosphorous excretion is principally dependent on regulation of
proximal tubule phosphorous reabsorption. A variety of factors influence renal tubular phosphate
reabsorption, and consequent urine excretion. Factors that increase urinary phosphorous excretion include
high phosphorous diet, parathyroid hormone, extracellular volume expansion, low dietary potassium
intake and proximal tubule defects (eg, Fanconi syndrome, X-linked hypophosphatemic rickets,
tumor-induced osteomalacia). Factors that decrease, or are associated with decreases in, urinary
phosphorous excretion include low dietary phosphorous intake, insulin, high dietary potassium intake, and
decreased intestinal absorption of phosphorous (eg, phosphate-binding antacids, vitamin D deficiency,
malabsorption states). A renal leak of phosphate has also been implicated as contributing to kidney stone
formation in some patients.
Useful For: Evaluation of hypo- or hyperphosphatemic states Evaluation of patients with
nephrolithiasis A timed 24-hour urine collection is the preferred specimen for measuring and interpreting
this urinary analyte. Random collections normalized to urinary creatinine may be of some clinical use in
patients who cannot collect a 24-hour specimen, typically small children. Therefore, this random test is
offered for children 0.34 0.34 0.34 0.33 0.33 0.32
0.22 0.21