Calcium
Calcium is a mineral for bones, muscles and nerves. Part of it is bound to albumin, so the two are often looked at together.
At a glance
- Sample
- Blood
- Units
- mg/dL (US), mmol/L (Europe)
- Often looked at with
- Magnesium, Phosphate
- Preparation
- No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting.
Units: mg/dL and mmol/L
US labs usually print calcium in mg/dL, most European labs in mmol/L. To convert, divide mg/dL by 4.0078.
mmol/L = mg/dL ÷ 4.0078 · molar mass 40.078 g/mol
This converter changes units only. It doesn’t tell you whether a number is in or out of any range: that depends on the range printed by your own lab, and on your doctor. Soma does not diagnose and is not medical advice.
Why lab ranges differ
Each lab sets its reference range for its own method and analyser, and many ranges differ by age and sex. Two labs can print different ranges for the same blood, so a result is read against the range on its own report, not against a number from another lab or a website.
Soma charts every calcium result against the range printed by the lab that measured it.
What can affect the result
- It depends on albumin: with less albumin, total calcium is lower too.
- A tourniquet left on for long raises it.
- Calcium supplements the day before.
If something like this applies, mention it to the doctor who reads your results.
Questions
How do I convert calcium from mg/dL to mmol/L?
Divide mg/dL by 4.0078. For example, 9.5 mg/dL is 2.37 mmol/L.
Why does my lab’s calcium range differ from another lab’s?
Each lab sets its range for its own method and equipment, and many ranges differ by age and sex. That’s why a result is best read against the range printed on the same report.
How do I prepare for a calcium test?
No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting. Follow your lab’s instructions.
Related tests
Got a lab report with Calcium?
Share it to Soma: it reads every row on your phone, with no account and no upload, and puts your calcium on one chart with your earlier results, each against the range your lab printed.
Sources
- Calcium Blood Test — MedlinePlus, U.S. National Library of Medicine.
- Units: PubChem: Calcium (calcium), molar mass 40.078 g/mol, as the Soma app converts.
Mention of a source doesn’t mean it endorses Soma. This page explains the test; it doesn’t diagnose and is not medical advice. Talk to your doctor about what your results mean.