PHOSPHATE (AS PHOSPHORUS)

Clinical Significance

Phosphate (as Phosphorus) - Serum phosphorus (Phosphate) levels alone are of limited diagnostic value and should be correlated with serum calcium levels. An increased phosphorus with decreased calcium suggests either hypoparathyroidism or renal disease. A decreased phosphorus and an increased calcium suggests hyperparathyroidism or sarcoidosis. When both calcium and phosphorus are decreased diagnostic considerations include malabsorption, vitamin D deficiency and renal tubular acidosis. Increased phosphorus and normal or increased calcium suggests Milk-alkali syndrome or hypervitaminosis D.

Preferred Specimen(s)
1 mL serum

Minimum Volume
0.5 mL

Transport Container
Serum Separator Tube (SST®)

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 72 hours
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria
Gross hemolysis • Plasma

Setup Schedule

Methodology
Spectrophotometry (SP)

Reference Range(s)
No age    2.5-4.5 mg/dL
<7 Days    4.0-9.0 mg.dL
7 Days-2 Years    4.0-8.0 mg/dL
3-12 Years     3.0-6.0 mg/dL
13-15 Years    3.2-6.0 mg/dL
16-18 Years    3.0-5.1 mg/dL
19-20 Years    2.7-5.0 mg/dL
21-64 Years    2.5-4.5 mg/dL
>64 Years    2.1-4.3 mg/dL

Alternative Name(s)
Phosphorus