The short answer
Your parathyroid glands hold blood calcium in a tight range, drawing on your bones when they need to. So the test tells you more about those glands than about the calcium you eat.1,7 A normal level is about 8.7 to 10.2 mg/dL.2
- A good result
- 8.7 to 10.2 mg/dL for most adults.2
- If yours is high
- The most common causes are an overactive parathyroid gland and cancer. A PTH test, done with calcium, tells them apart.1,4
- Should you test?
- It’s part of the standard metabolic panel. It matters most if you’ve had kidney stones or thin bones, or take lithium or a water pill.1
Check your result
Type the number from your report. It stays on this page.
- Very low Under 7.6
- Low 7.6 to 8.6
- Normal 8.7 to 10.2
- Mildly high 10.3 to 11.9
- High 12.0 to 13.9
- Very high 14.0 or more
Enter your result to see what it means and what to do next.
Got a result from another lab? Ask Picardo about it. The app explains your results, and a physician can follow up.
High bands from the Endocrine Society; the very low line is from the UK Society for Endocrinology. Both were set for albumin-adjusted calcium.3,5 Labcorp’s range is 8.7 to 10.2 for most adults.2 The bar isn’t to scale.
Very low: go to an emergency department today
Below about 7.6, low calcium often causes symptoms, such as tingling around your mouth and in your fingers, muscle cramps and spasms and, rarely, seizures or heart rhythm problems.5
Go to an emergency department today, even if you feel well, and right away if you have spasms, a racing heart or a seizure. UK emergency guidance treats calcium this low as an emergency.5
Low: find out if it’s real
About half the calcium in your blood rides on proteins, mainly albumin, so low albumin can pull the total down. That doesn’t prove your active calcium is fine, though; ionized calcium settles it.2,6 A real shortage can come from kidney disease, very low vitamin D, low magnesium or damage to the parathyroid glands during neck surgery.2,5 If you’re a man over 59, Labcorp’s range starts at 8.6.2
Not urgent if you feel well. See a clinician in the next week or two. If you have tingling around your mouth or in your fingers, cramps or spasms, get care the same day.5
- 1 Look at your albumin, which is on the same panel.
- 2 Check vitamin D and magnesium.5
- 3 Ask about ionized calcium, which measures your active calcium directly.6
Normal
Your calcium is in the normal range.2
Nothing to worry about.
- 1 Nothing to do. A normal result doesn’t tell you whether you eat enough calcium; your bones keep the blood level steady.7
Mildly high: check PTH
Nine times out of ten, high calcium comes from an overactive parathyroid gland (primary hyperparathyroidism) or from cancer.4 Water pills, lithium and too much vitamin D or calcium can raise it too, and being short of fluids can nudge it up slightly.1,2,4 If you’re a woman over 59, Labcorp’s range runs to 10.3.2
Not urgent. Worth sorting out over the next few weeks.
- 1 Repeat calcium with parathyroid hormone (PTH). High calcium with a high or normal PTH points to primary hyperparathyroidism; a low PTH points to other causes.1,4
- 2 List any water pills, lithium, calcium or vitamin D you take.1,4
- 3 Check vitamin D. In primary hyperparathyroidism, guidelines aim to keep it above 30 ng/mL, but not high.1
High: see a clinician within days
This is moderately high.3 It can cause thirst, passing a lot of urine, constipation, nausea and confusion, and it usually needs treatment soon.3,4
See a clinician today. If you’re vomiting, confused or very drowsy, go to an emergency department now.4
- 1 Stop calcium and vitamin D supplements until you’ve been seen.
- 2 Ask for PTH to be checked with calcium, to find the cause.1
Very high: go to an emergency department
At 14 or higher, high calcium needs urgent treatment, because it can cause heart rhythm problems and, at worst, coma.4
Go to an emergency department now.
- 1 Take this result and a list of your medicines and supplements with you.
What is a normal calcium level?
Labcorp’s range is 8.7 to 10.2 mg/dL for adults up to 59. Over 59, it’s 8.6 to 10.2 for men and 8.7 to 10.3 for women.2 Outside it, guidelines grade calcium like this:3,5
Very low: go to an emergency department today
Below about 7.6, low calcium often causes symptoms, such as tingling around your mouth and in your fingers, muscle cramps and spasms and, rarely, seizures or heart rhythm problems.5
Go to an emergency department today, even if you feel well, and right away if you have spasms, a racing heart or a seizure. UK emergency guidance treats calcium this low as an emergency.5
Low: find out if it’s real
About half the calcium in your blood rides on proteins, mainly albumin, so low albumin can pull the total down. That doesn’t prove your active calcium is fine, though; ionized calcium settles it.2,6 A real shortage can come from kidney disease, very low vitamin D, low magnesium or damage to the parathyroid glands during neck surgery.2,5 If you’re a man over 59, Labcorp’s range starts at 8.6.2
Not urgent if you feel well. See a clinician in the next week or two. If you have tingling around your mouth or in your fingers, cramps or spasms, get care the same day.5
Normal
Your calcium is in the normal range.2
Nothing to worry about.
- 1 Nothing to do. A normal result doesn’t tell you whether you eat enough calcium; your bones keep the blood level steady.7
Mildly high: check PTH
Nine times out of ten, high calcium comes from an overactive parathyroid gland (primary hyperparathyroidism) or from cancer.4 Water pills, lithium and too much vitamin D or calcium can raise it too, and being short of fluids can nudge it up slightly.1,2,4 If you’re a woman over 59, Labcorp’s range runs to 10.3.2
Not urgent. Worth sorting out over the next few weeks.
- 1 Repeat calcium with parathyroid hormone (PTH). High calcium with a high or normal PTH points to primary hyperparathyroidism; a low PTH points to other causes.1,4
- 2 List any water pills, lithium, calcium or vitamin D you take.1,4
- 3 Check vitamin D. In primary hyperparathyroidism, guidelines aim to keep it above 30 ng/mL, but not high.1
High: see a clinician within days
This is moderately high.3 It can cause thirst, passing a lot of urine, constipation, nausea and confusion, and it usually needs treatment soon.3,4
See a clinician today. If you’re vomiting, confused or very drowsy, go to an emergency department now.4
- 1 Stop calcium and vitamin D supplements until you’ve been seen.
- 2 Ask for PTH to be checked with calcium, to find the cause.1
Very high: go to an emergency department
At 14 or higher, high calcium needs urgent treatment, because it can cause heart rhythm problems and, at worst, coma.4
Go to an emergency department now.
- 1 Take this result and a list of your medicines and supplements with you.
What is blood calcium?
Think of your bones as a calcium bank and your blood as the checking account. Your parathyroid glands move calcium between them to keep the balance steady, so the blood number tells you about the glands, not your diet.
Almost all your calcium, about 98%, is in your bones.7 The small amount in your blood keeps your nerves, muscles and heartbeat working. Four small glands in your neck, the parathyroids, hold it steady with parathyroid hormone (PTH).1
About half the calcium in your blood is bound to proteins, mostly albumin, and the rest is free. The standard test measures both together.2
What causes high calcium?
- Primary hyperparathyroidism, where a parathyroid gland makes too much PTH. In the US, it affects about 233 in 100,000 women and 85 in 100,000 men.1
- Cancer3,4
- Water pills (thiazide diuretics) and lithium1,4
- Too much vitamin D, or calcium from supplements or antacids4,7
- Less often, sarcoidosis, an overactive thyroid, long bed rest or an inherited condition called familial hypocalciuric hypercalcemia1,4
Primary hyperparathyroidism is diagnosed when high calcium and a high or normal PTH show up on two tests at least 2 weeks apart.1 Surgery is recommended if any of these apply:1
- Calcium more than 1 mg/dL above the lab’s upper limit
- Osteoporosis or a spine fracture
- Kidney stones, or reduced kidney function
- A lot of calcium in your urine
- Age under 50
What causes low calcium?
- Low albumin, which can pull the total down without a real shortage2,6
- Kidney disease2
- Low vitamin D5
- Low magnesium, which can come from long-term acid-reducers5
- Damage to the parathyroid glands during thyroid or neck surgery5
Is “corrected calcium” accurate?
Not very. Many labs and clinicians adjust calcium for albumin with a formula. But in April 2026, the international bodies for bone health and lab medicine said labs should stop reporting it, because it often gets the answer wrong, especially when albumin is low.6
They recommend measuring ionized (free) calcium instead when a decision depends on it.6
How to lower high calcium
- Parathyroid surgery
Removing the overactive gland cures primary hyperparathyroidism. Guidelines recommend it when calcium or its effects pass set thresholds, and it’s an option for others.1
- How much it helps
- A lot
- How sure we are
- Very sure
- Cinacalcet
A pill that brings calcium down in primary hyperparathyroidism when surgery isn’t an option. It doesn’t cure the gland.1
- How much it helps
- Some
- How sure we are
- Very sure
- Stopping what’s raising it
Extra calcium and vitamin D supplements can be stopped. Water pills and lithium need a clinician’s advice first.1,4
- How much it helps
- Some
- How sure we are
- Fairly sure
Should you take calcium supplements?
Food first. US guidance is to meet your needs mainly through diet.7 Adults need 1,000 mg a day, rising to 1,200 mg for women over 50 and men over 70. Don’t go above 2,000 to 2,500 mg a day in total.7
Supplements prevent few fractures in people living at home. A 2026 review of 69 trials found that any benefit from calcium, vitamin D or both was too small to matter.8 In a December 2024 draft that isn’t final yet, the US Preventive Services Task Force recommends against vitamin D, with or without calcium, to prevent fractures in women after menopause and men 60 and older.9 Extra calcium from supplements may raise your risk of kidney stones, and studies disagree on whether it adds to heart risk. A US panel of bone and heart experts concluded that calcium from food or supplements neither raises nor lowers heart risk.7
If you take a supplement, your body absorbs it best in doses of 500 mg or less at a time.7
Who should get a calcium test?
It’s part of the standard metabolic panel. It’s most worth checking if:
- You’ve had kidney stones.1
- You have osteoporosis or a spine fracture.1
- You take lithium or a thiazide water pill.1
- You take high doses of vitamin D or calcium.4
- You’ve had thyroid or neck surgery.5
- You’re thirsty all the time, pass a lot of urine or are often constipated.3
How to get a calcium test, and what it costs
It comes from the comprehensive metabolic panel, which costs $4.00 through Picardo.
Comprehensive metabolic panel
The test this number comes from.
- Results in 2 to 3 days, in the app
- Physician follow-up if you want one
- Free Labcorp draw, or $75 at home
- No other fees. HSA and FSA eligible.
It’s also part of the Base Core Annual – Men, Base Core Annual – Women, Heart Health, Brain Health Screening, Pregnancy, Postpartum, Fertility, Thyroid & Autoimmunity and Celiac / GI panels, if you’d rather test more at once.
Already have a result? Ask Picardo about itQuestions people ask
What is a PTH test?
Parathyroid hormone, the hormone your parathyroid glands make. Measured with calcium, it shows whether those glands are behind a high or low result.1
Can high calcium cause kidney stones?
Yes. Kidney stones are one of the signs that primary hyperparathyroidism is affecting your body, and one of the reasons guidelines recommend surgery for it.1
Does eating more calcium raise your blood calcium?
Not in a healthy person. Almost all your calcium, about 98%, sits in your bones, and your body uses them to keep the blood level steady.7
What is normocalcemic hyperparathyroidism?
It’s when PTH stays high while calcium stays normal on repeated tests over 3 to 6 months. It’s only diagnosed after other causes, such as low vitamin D and kidney disease, are ruled out.1
Do I need to fast for a calcium test?
The metabolic panel it comes on asks for a 12-hour fast, for its glucose result. Labcorp also prefers a morning, fasting sample for calcium, because it varies a little through the day.2
Often checked alongside
Test details
- Labcorp test
- Metabolic Panel (14), Comprehensive, 322000
- LOINC
- 17861-6
- Sample
- Blood
- Fasting
- 12 hours for the metabolic panel. Labcorp also prefers a morning, fasting sample for calcium.2
- Typical lab range
- 8.7 to 10.2 mg/dL at ages 18 to 59; over 59, 8.6 to 10.2 for men and 8.7 to 10.3 for women2
- Measures
- Total calcium, both the part bound to proteins and the free part2
- Units
- mg/dL in the US. For mmol/L, divide by 4.
Sources
- 1 Bilezikian JP, Khan AA, Silverberg SJ, et al. Evaluation and management of primary hyperparathyroidism: summary statement and guidelines from the Fifth International Workshop. J Bone Miner Res. 2022;37(11):2293–2314. doi.org/10.1002/jbmr.4677
- 2 Labcorp. Calcium, test 001016. Labcorp test menu. Accessed October 28, 2026. www.labcorp.com/tests/001016/calcium
- 3 El-Hajj Fuleihan G, Clines GA, Hu MI, et al. Treatment of hypercalcemia of malignancy in adults: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2023;108(3):507–528. doi.org/10.1210/clinem/dgac621
- 4 Walsh J, Gittoes N, Selby P; Society for Endocrinology Clinical Committee. Society for Endocrinology endocrine emergency guidance: emergency management of acute hypercalcaemia in adult patients. Endocr Connect. 2016;5(5):G9–G11. doi.org/10.1530/EC-16-0055
- 5 Turner J, Gittoes N, Selby P; Society for Endocrinology Clinical Committee. Society for Endocrinology endocrine emergency guidance: emergency management of acute hypocalcaemia in adult patients. Endocr Connect. 2016;5(5):G7–G8. doi.org/10.1530/EC-16-0056
- 6 Cavalier E, Zima T, Plebani M, et al. Albumin-adjusted (“corrected”) calcium should no longer be reported: a position statement from the Joint IOF Working Group and IFCC Committee on Bone Metabolism and EFLM Committee on CKD. Clin Chem Lab Med. 2026;64(8):1719–1721. doi.org/10.1515/cclm-2026-0545
- 7 Office of Dietary Supplements, National Institutes of Health. Calcium: fact sheet for health professionals. Updated June 22, 2026. ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
- 8 Massé O, Mercurio CM, Dupuis S, et al. Calcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis. BMJ. 2026;393:e088050. doi.org/10.1136/bmj-2025-088050
- 9 US Preventive Services Task Force. Vitamin D, calcium, or combined supplementation for the primary prevention of falls and fractures in community-dwelling adults: preventive medication. Draft recommendation statement. December 17, 2024. www.uspreventiveservicestaskforce.org/uspstf/draft-recommendation/vitamin-d-calcium-combined-supplementation-primary-prevention-falls-fractures-communitydwelling-adults
Updated 28 Oct 2026.
This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.