| Laboratory: | Clinical Biochemistry | ||||
| Test Name: |
CALCIUM - (U)
Test Code:
CAU
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| Clinical Information: |
Calcium is the most abundant mineral in the body with about 99% in bone as hydroxyapatite. The remaining 1% is distributed in various tissues and extracellular fluids. In serum, about 40% is bound to albumin, 10% is present as inorganic complexes, and 50% is present as free or ionized calcium. The concentration of calcium in serum and extracellular fluid is very tightly controlled and it is excreted by urine and feces. Increased calcium excretion is associated with kidney stone risk.
Urine calcium determination is useful in the diagnosis and management of disorders such as kidney stone risk, bone and parathyroid disease. Reference values are based on normal diet. |
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| Collection Devices: |
Collect 24h urine without preservative.
Collect random urine after the first voiding in the morning. (ie. overnight urine is not acceptable). Refrigerate 24h and random urine specimens until analysis. Similar lab approved leak-proof containers acceptable. |
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| Specimen Required: |
Urine: 3.0 mL
Stability 4 days refrigerated, |
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| Referral: |
Urine: 3.0 mL
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| Requisition: | |||||
| Reference Values: |
24 HOUR
Males: ≤ 6.9 mmol/d Females: ≤ 6.2 mmol/d (mmol/d x 40 = mg/d) RANDOM ≥ 18 y: Calcium/Creatinine: 0.04 - 0.30 mmol/mmol |
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| Availability: |
Weekdays
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| See Also: | |||||
| More Information: |
If random urine, specify.
If 24h urine, measure and record volume. Refrigerate 24h and random urine specimens until analysis. |