Phosphorus, Blood is a topic covered in the Davis's Lab & Diagnostic Tests.

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Inorganic phosphorus, phosphate, PO4.

Common Use:
To assist in evaluating multiple body system functions by monitoring phosphorus levels in relation to other electrolytes. Used specifically to evaluate renal function in at-risk patients.

Serum collected in a gold-, red-, or red/gray-top tube. Plasma collected in green-top (heparin) tube is also acceptable.

Normal Findings:
(Method: Spectrophotometry)

AgeConventional UnitsSI Units (Conventional Units × 0.323)
0–5 d4.6–8 mg/dL1.5–2.6 mmol/L
1–3 yr3.9–6.5 mg/dL1.3–2.1 mmol/L
4–6 yr4–5.4 mg/dL1.3–1.7 mmol/L
7–11 yr3.7–5.6 mg/dL1.2–1.8 mmol/L
12–13 yr3.3–5.4 mg/dL1.1–1.7 mmol/L
14–15 yr2.9–5.4 mg/dL0.9–1.7 mmol/L
16–19 yr2.8–4.6 mg/dL0.9–1.5 mmol/L
Adult2.5–4.5 mg/dL0.8–1.4 mmol/L
Values may be slightly decreased in older adults due to dietary insufficiency or the effects of medications and the presence of multiple chronic or acute diseases with or without muted symptoms.

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