Calcium

Clinical Chemistry

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Description

Calcium is the most abundant mineral element in the body with around 99 percent in the bone and 1% of that being freely exchangeable with calcium in the plasma. In plasma around 40% is bound to protein (mostly albumin). Ionized (free) calcium is the biologically active form, however, it is the total calcium levels which are most often measured. Total calcium levels can be affected by changes in albumin and therefore levels are adjusted for albumin concentration and adjusted calcium concentration reported. Plasma calcium levels are controlled mostly by parathyroid hormone (PTH) and vitamin D. An imbalance in either of these can lead to changes in plasma/serum calcium levels.

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Indications

Signs/symptoms of hypo/hypercalcaemia. Conditions known to cause hypo/hypercalcaemia e.g. renal disease and malignancy. Management of patients with hypo/hypercalcaemia. Metabolic bone disease investigations (part of bone profile).

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Sample Type

Serum. SST, Gel, minimum 2mL (1mL separated serum). 24 hour urine, no preservative.
For exclusion of FHH a paired fasting serum and random urine sample are required.

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Reference Range

Reference ranges are provided on the report. Alternatively, please contact the laboratory for current ranges.

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Turnaround Time

Within 1 day

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Testing Frequency

As required.

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Patient Preparation

No special preparation but sera from patients receiving EDTA therapy are unsuitable for analysis. Paired urine and serum samples for exclusion of familial hypocalciuric hypercalcaemia (FHH) should be fasting.

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.