Atomic Number:	20
Atomic Symbol:	Ca
Atomic Weight:	40.08
Electron Configuration:	[Ar]4s2

Approximately 99% of the Ca is located within bone and teeth to provide structural support within the human body. The remaining 1% is found within intracellular and extracellular fluids and serves in its ionized form as a messenger in signal transduction. About 45% of calcium is albumin bound. Depressed albumin levels are the most common cause of low total calcium values. Suggested approximate correction factor: add 0.25 mmol/L to calcium value for each 10 g/L that albumin falls below 40 g/L. A reduced blood Ca can result in low tissue Ca presenting with irritability of the CNS tissue, cardiac abnormalities, and skeletal muscle cramping (tetany).

Ca is mobilized in the skeletal muscle at about 0.5 g/day and varies with age, diet, hormonal status and physiological state. A deficiency of Ca can result from decreased intake, poor absorption, increased excretion or hormonal imbalance. Bones are affected with poor mineralization and result in rickets during the growing years in children, and osteomalacia in adults. If mobilization from the skeletal bone exceeds deposition, the bone becomes porous and develop osteoporosis. Osteoporosis in older women due to loss of total bone mass is caused by a multiple etiology of low calcium, estrogen and lack of exercise.

Calcium (hair)?Hair calcium is determined as part of the panel of 38 elements available in hair. Reference values have been established (400?1500 ug/g) which show a wide range, in contrast to serum calcium which have tight limits except in serious pathologies. Calcium accumulation in hair can reflect its chronic mobilization from bone with calcium loss. High hair calcium can be seen in older women with indications of osteoporosis. Hair calcium concentrations are inversely correlated to that of the aorta. In adults, low calcium in hair has been seen in cases of myocardial infarction, with increased aortic calcium levels (Trace Elem Res 1981;12:383?7). During the active growing years in children, there is a rapid uptake by osteocytes of bone with a lower hair calcium. This may not directly be related to dietary intake of calcium.
Sample Requirements (click on a Sample Type)
 

Urine

Hair

Reference range

Analyte  Calcium
Random Urine	24 Hour Urine	Hair
66.8 - 200 mg/L 1.67 - 5.00 mmol/L 220.0 - 658.0 mmol/mol creatinine	2.50 - 7.50 mmol/d	300.0 -1000.0 ug/g 7.5 - 25.0 umol/g

 

Method of Analysis:  High Resolution ICP/MS

Test available:  Monday - Friday 0800 - 1600 h
Turnaround Time:  Average 5-10 days
Maximum 10 days

January 15, 2010