Calcium
Calcium is a mineral for bones, muscles, nerves and blood clotting. In the blood the body carefully regulates it with hormones (PTH) and vitamin D — only a small part of all calcium is in the blood, most is in the bones.
| Rating | Range | What it means |
|---|---|---|
| Talk to a doctor | below 2.15 mmol/L | |
| Good | 2.15 – 2.51 mmol/L | Within the reference range. |
| Talk to a doctor | 2.51 mmol/L and above |
Why it matters
An abnormal value points to the parathyroid glands, vitamin D, or the kidneys.
If it’s low
Low calcium can cause tingling, cramps, irritability; the cause is often vitamin D deficiency or a PTH disorder.
If it’s high
High calcium (hypercalcemia) can cause fatigue, thirst, constipation, kidney stones; the cause is often too much PTH or (more rarely) disease.
What to do
Interpret it with PTH and vitamin D — they tell the cause. Do not supplement high calcium; find the cause. Low calcium often follows once vitamin D is corrected.
Read together with
Parathyroid hormone (PTH) · Vitamin D · Phosphate · Albumin
Part of the guide: Vitamins & minerals →
Articles about this marker
- Albumin blood test: what low or high albumin meansMarker explained
- Alkaline phosphatase (ALP): what high or low levels meanMarker explained
- Vitamin D: what your value means and how to raise your levelMarker explained
This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.
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