A calcium or bone profile blood test is used to check mineral balance, bone-related markers and sometimes clues about kidney, liver, parathyroid and vitamin D health. It is a common blood test, but the results can be confusing because calcium is not interpreted on its own. Doctors often look at adjusted calcium, phosphate, alkaline phosphatase, albumin and related tests before deciding what the result means.
You may have a bone profile as part of a routine health check, investigation for tiredness, bone pain, muscle cramps, kidney stones, abnormal vitamin D, osteoporosis risk, liver or kidney problems, or monitoring of an existing condition. It may also be included in private blood test packages under names such as “bone profile”, “bone screen”, “calcium profile” or “bone health blood test”.
The most important thing to know is this: an abnormal calcium or bone profile result does not automatically mean you have a serious bone disease. Some results are mild, temporary or related to albumin levels, vitamin D, kidney function, medication or recent illness. But some abnormal results do need prompt medical review, especially if calcium is very high or very low, or if you have symptoms.
This guide explains what calcium and bone profile blood tests measure, what high and low results may mean, how adjusted calcium differs from total calcium, when vitamin D, PTH and magnesium matter, and when to speak to a GP or clinician.
Important: This article is for general information only and should not replace medical advice. If your calcium is very high or very low, or you have confusion, severe weakness, dehydration, fainting, chest pain, severe abdominal pain, repeated vomiting, seizures, irregular heartbeat or feel very unwell, seek urgent medical advice.
What is a calcium or bone profile blood test?
A calcium blood test measures the amount of calcium in your blood. A bone profile is a group of related blood tests that gives a broader picture of calcium balance and bone-related chemistry.
Despite the name, a bone profile does not directly measure bone strength. It does not diagnose osteoporosis on its own, and it does not show whether you have a fracture. Instead, it looks at minerals and enzymes linked with bones, kidneys, liver, parathyroid glands and general metabolism.
A standard bone profile commonly includes:
- Total calcium
- Adjusted calcium, also called corrected calcium
- Albumin
- Phosphate
- Alkaline phosphatase, often shortened to ALP
Some laboratories may also include total protein, globulins or other related markers. However, vitamin D, parathyroid hormone, magnesium and bone turnover markers are often separate tests that must be requested specifically. This is important because people often assume a “bone profile” automatically checks vitamin D or osteoporosis risk, but it usually does not give the full picture by itself.
If you are trying to understand several blood tests together, you may also find How to Understand Blood Test Results useful.
What does each part of a bone profile measure?
A bone profile is useful because each marker tells a slightly different part of the story. The pattern matters more than one number alone.
Total calcium
Total calcium is the overall amount of calcium measured in the blood. Calcium is essential for bones, teeth, muscles, nerves, blood clotting and heart rhythm. Most calcium in the body is stored in bones, but a small amount circulates in the blood and is tightly controlled.
Calcium levels are regulated mainly by parathyroid hormone, vitamin D, the kidneys and the bones. This is why abnormal calcium can be linked with parathyroid problems, vitamin D deficiency, kidney disease, certain medicines, dehydration, bone disease or, less commonly, cancer-related causes.
Adjusted calcium
Adjusted calcium, also called corrected calcium, is calcium adjusted for albumin level. This matters because some calcium in the blood is bound to albumin, a protein made by the liver.
If albumin is low, total calcium may look low even when the active calcium level is not truly low. Adjusted calcium is used to estimate calcium more accurately in many routine situations.
Albumin
Albumin is a protein made by the liver. It helps keep fluid in the bloodstream and carries various substances, including part of the calcium in your blood.
Albumin is included in a bone profile partly because it helps calculate adjusted calcium. Low albumin can occur with inflammation, liver disease, kidney disease, malnutrition, severe illness, gut protein loss or other long-term health problems.
Phosphate
Phosphate is a mineral involved in bones, teeth, energy production and cell function. It works closely with calcium, vitamin D, parathyroid hormone and kidney function.
Phosphate abnormalities may be linked with kidney disease, parathyroid conditions, vitamin D problems, malnutrition, alcohol-related illness, refeeding after poor intake, some medicines and rare inherited conditions.
Alkaline phosphatase
Alkaline phosphatase, or ALP, is an enzyme found mainly in the liver and bones. In a bone profile, ALP can provide clues about bone turnover or liver and bile duct problems.
A raised ALP may come from bone or liver. This is why ALP is often interpreted alongside liver tests such as ALT, AST, GGT and bilirubin. If ALP is raised and GGT is also raised, the source may be more likely to be liver or bile duct related. If ALP is raised with normal liver markers, a bone source may be considered.
For more on liver-related interpretation, see ALT, AST, ALP and GGT Liver Results Explained and Liver Function Test Results Explained.
What are normal calcium and bone profile results?
Normal ranges vary between laboratories, so always compare your result with the reference range printed on your own report. Results are usually reported in mmol/L for calcium and phosphate, g/L for albumin, and U/L for ALP.
As a broad UK guide, typical adult reference ranges may look something like this:
| Test | Common broad guide range | How to think about it |
|---|---|---|
| Total calcium | Often around 2.2 to 2.6 mmol/L | Needs interpretation with albumin and adjusted calcium. |
| Adjusted calcium | Often around 2.2 to 2.6 mmol/L | Usually more useful than total calcium when albumin is abnormal. |
| Albumin | Often around 35 to 50 g/L | Low albumin can affect total calcium interpretation. |
| Phosphate | Often around 0.8 to 1.5 mmol/L | Interpreted with calcium, vitamin D, PTH and kidney function. |
| ALP | Often around 30 to 130 U/L | May come from bone or liver; age and pregnancy affect interpretation. |
These values are only a guide. Children and teenagers often have higher ALP because bones are growing. Pregnant people may also have raised ALP because the placenta produces ALP. Older adults, people with kidney disease, people on certain medicines and people with chronic illness may need more individual interpretation.
A result just outside the range is usually interpreted differently from a result that is far outside the range. Your symptoms and related blood tests matter.
High calcium results: what hypercalcaemia may mean
High blood calcium is called hypercalcaemia. Mild hypercalcaemia may cause no symptoms and may be found on a routine blood test. More significant hypercalcaemia can cause symptoms and sometimes needs urgent medical assessment.
Common symptoms of high calcium can include:
- tiredness or weakness
- thirst
- passing urine more often
- constipation
- nausea or vomiting
- abdominal pain
- low mood or confusion
- muscle weakness
- bone pain
- kidney stones
- dehydration
The NHS lists symptoms of hyperparathyroidism, one common cause of high calcium, including tiredness, aches and pains, muscle weakness, nausea, constipation, thirst, passing urine more often, low mood and depression. You can read more on the NHS hyperparathyroidism page.
Primary hyperparathyroidism
One common cause of high calcium is primary hyperparathyroidism. The parathyroid glands are small glands in the neck that help control calcium levels. If one or more glands produce too much parathyroid hormone, calcium can rise.
Primary hyperparathyroidism is often found on routine blood tests. Some people have no symptoms. Others have kidney stones, bone thinning, fatigue, constipation, mood changes, muscle weakness or aches and pains.
If high calcium is found, your GP may request parathyroid hormone, often called PTH, as a follow-up test. PTH helps distinguish between different causes of high calcium.
Vitamin D and calcium supplements
Taking too much vitamin D or calcium can sometimes raise calcium levels, especially if doses are high or if kidney function is reduced. Some people take multiple supplements without realising the total dose.
If calcium is high, tell your clinician about all supplements, including vitamin D drops, multivitamins, calcium tablets, antacids, bodybuilding supplements and over-the-counter products.
For more detail, see Vitamin D Blood Test Results Explained.
Medicines
Some medicines can contribute to high calcium. These may include thiazide diuretics, lithium and some high-dose vitamin or mineral supplements. Do not stop prescribed medication without medical advice, but make sure your GP knows what you take.
Kidney disease
Kidney function is closely linked with calcium and phosphate balance. Chronic kidney disease can disturb mineral levels, vitamin D activation and parathyroid hormone regulation.
If calcium or phosphate is abnormal, kidney blood tests such as creatinine, eGFR, urea and electrolytes may be checked. See Kidney Blood Test Results Explained, eGFR and Creatinine Results Explained and U&E Blood Test Results Explained.
Cancer-related high calcium
High calcium can sometimes occur in people with cancer, especially if cancer affects bone or produces hormone-like substances that raise calcium. However, high calcium does not automatically mean cancer. Many people with high calcium have non-cancer causes such as primary hyperparathyroidism.
High calcium is more concerning if it is significantly raised, new, unexplained, or linked with symptoms such as weight loss, bone pain, severe fatigue, night sweats or feeling very unwell.
If your calcium is high, do not assume the cause. Ask your GP what follow-up tests are needed.
When high calcium is urgent
Seek urgent medical advice if high calcium is associated with confusion, severe dehydration, repeated vomiting, severe weakness, severe abdominal pain, fainting, drowsiness, irregular heartbeat or feeling seriously unwell.
If a private blood test provider tells you your calcium is critically high, contact urgent medical services rather than waiting for a routine appointment.
Low calcium results: what hypocalcaemia may mean
Low blood calcium is called hypocalcaemia. Mild low calcium may cause no symptoms, especially if it is related to low albumin and adjusted calcium is normal. True low adjusted calcium can cause symptoms and may need prompt assessment.
Possible symptoms of low calcium include:
- tingling around the mouth
- pins and needles in the hands or feet
- muscle cramps or spasms
- twitching
- fatigue
- anxiety or irritability
- seizures in severe cases
- abnormal heart rhythm in severe cases
Low calcium should be interpreted carefully. A low total calcium may not be a true calcium problem if albumin is low. Adjusted calcium is often more useful.
Vitamin D deficiency
Vitamin D helps your body absorb calcium from food. Low vitamin D can contribute to low calcium, low phosphate, raised ALP and bone problems such as osteomalacia in adults or rickets in children.
Vitamin D deficiency is common in the UK, especially in people who get little sunlight, have darker skin, cover most of their skin outdoors, are housebound, live in care homes, are pregnant or breastfeeding, or have conditions affecting absorption.
If calcium or ALP is abnormal, vitamin D may be checked separately. A standard bone profile does not always include vitamin D.
Low parathyroid hormone
Low calcium can occur if the parathyroid glands do not produce enough PTH. This may happen after thyroid or neck surgery, autoimmune disease, genetic causes or other rare conditions.
If adjusted calcium is low, your doctor may check PTH, magnesium, phosphate, vitamin D and kidney function.
Magnesium deficiency
Magnesium is important for parathyroid hormone function and calcium balance. Low magnesium can contribute to low calcium that is difficult to correct until magnesium is treated.
Magnesium is not always included in a standard bone profile, so it may need to be requested separately. Low magnesium may be linked with poor intake, diarrhoea, alcohol use, some medicines, diabetes, kidney issues or gut absorption problems.
Kidney disease and phosphate problems
Kidney disease can affect calcium, phosphate, vitamin D and PTH. In chronic kidney disease, phosphate may rise, active vitamin D may fall and parathyroid hormone may increase. This can affect bone health over time.
This is why calcium and phosphate results are often interpreted alongside kidney function tests.
When low calcium is urgent
Low calcium may need urgent help if there are seizures, severe muscle spasms, fainting, confusion, chest pain, irregular heartbeat, severe tingling or symptoms after neck surgery.
If you are told your calcium is critically low, seek urgent medical advice.
Phosphate, ALP and albumin results explained
Calcium is only one part of a bone profile. Phosphate, ALP and albumin can change the interpretation significantly.
High phosphate
High phosphate may be linked with kidney disease, high phosphate intake from some medicines or supplements, low parathyroid hormone, cell breakdown, severe illness or laboratory-related factors.
In chronic kidney disease, phosphate can rise because the kidneys are less able to remove it. This can contribute to mineral and bone disorders over time.
If phosphate is high, kidney function, calcium, PTH and vitamin D may be checked.
Low phosphate
Low phosphate can occur with vitamin D deficiency, overactive parathyroid glands, poor nutrition, alcohol-related illness, some medicines, refeeding after starvation, severe illness or certain inherited conditions.
Low phosphate can cause muscle weakness, bone pain, fatigue and, if severe, more serious symptoms. Mild low phosphate may be temporary, but persistent or significant low phosphate needs medical review.
High ALP
High ALP can come from bone or liver. In children and teenagers, ALP is often higher because bones are growing. In adults, raised ALP may be linked with liver or bile duct disease, vitamin D deficiency, Paget’s disease of bone, healing fractures, bone metastases, hyperparathyroidism or pregnancy.
To work out whether ALP is more likely from liver or bone, doctors often check GGT and other liver tests. If GGT is raised too, a liver or bile duct source may be more likely. If GGT and other liver markers are normal, a bone source may be considered.
For a more detailed explanation, see ALT, AST, ALP and GGT Liver Results Explained.
Low ALP
Low ALP is less common. It may be seen with malnutrition, zinc deficiency, hypothyroidism, severe anaemia, some genetic bone conditions or laboratory variation. Mild low ALP is often not urgent, but persistent low ALP should be interpreted with symptoms and other results.
Low albumin
Low albumin can make total calcium appear low. It can also suggest wider health issues such as inflammation, liver disease, kidney disease, poor nutrition, severe illness or protein loss from the gut or kidneys.
If albumin is low, adjusted calcium becomes particularly important. Your GP may also review liver function, kidney function, urine protein, inflammatory markers and nutritional status.
Bone profile and bone health: osteoporosis, vitamin D and fractures
A bone profile can provide clues about bone metabolism, but it does not directly measure bone density. If osteoporosis is suspected, the key test is usually a DEXA scan, also called a bone density scan.
Osteoporosis means bones are weaker and more likely to fracture. It is common after menopause, in older adults, in people taking long-term steroids, people with low body weight, people with previous fragility fractures, and those with certain medical conditions.
A bone profile may be used to look for treatable contributors to bone problems, such as calcium imbalance, vitamin D deficiency, raised ALP, kidney disease or parathyroid problems. But a normal bone profile does not rule out osteoporosis.
Vitamin D and bone profile
Vitamin D helps absorb calcium and supports bone mineralisation. Low vitamin D may cause bone pain, muscle aches, weakness and raised ALP in some cases. Severe deficiency can lead to osteomalacia in adults.
Because vitamin D is often not included in a standard bone profile, you may need a separate vitamin D test if deficiency is suspected. See Vitamin D Blood Test Results Explained.
Osteoporosis and blood tests
Blood tests may help look for secondary causes of osteoporosis. These can include vitamin D deficiency, thyroid disease, parathyroid disease, kidney disease, liver disease, coeliac disease, inflammatory disease and some hormone problems.
If low calcium, low vitamin D, anaemia or gut symptoms are present, coeliac disease may sometimes be considered. See Coeliac Blood Test Results Explained.
Bone pain and raised ALP
Bone pain with raised ALP may need further assessment. Possible causes include vitamin D deficiency, Paget’s disease of bone, healing fracture, hyperparathyroidism, inflammatory bone conditions or, less commonly, cancer-related bone disease.
If you have persistent bone pain, unexplained fracture, weight loss, night sweats or worsening symptoms, speak to a GP.
How calcium and bone profile results are interpreted with other tests
Calcium and bone profile results are rarely interpreted alone. Doctors usually look for patterns across multiple tests.
Parathyroid hormone
Parathyroid hormone, or PTH, is one of the most important follow-up tests when calcium is abnormal.
If calcium is high and PTH is also high or not appropriately low, primary hyperparathyroidism may be considered. If calcium is high and PTH is suppressed, other causes may be investigated.
If calcium is low, PTH helps show whether the parathyroid glands are responding properly.
Vitamin D
Vitamin D helps explain some low calcium, low phosphate or raised ALP patterns. It may also be checked when bone pain, muscle aches, osteoporosis risk or deficiency risk factors are present.
Kidney function
Creatinine, eGFR, urea and electrolytes help assess kidney function. Kidneys are central to calcium, phosphate and vitamin D regulation. Abnormal kidney function can change the interpretation of calcium and phosphate results.
Liver function
Liver tests help interpret ALP and albumin. Raised ALP may come from liver or bone, and low albumin may reflect liver disease, inflammation, kidney disease or nutrition.
Full blood count and inflammation markers
A full blood count, CRP and ESR can help identify anaemia, inflammation or infection. These may be relevant if bone profile results are abnormal alongside tiredness, weight loss, pain or long-term symptoms.
Related guides include Full Blood Count Results Explained, CRP and Inflammation Blood Test Results Explained and ESR Blood Test Results Explained.
Thyroid tests
Thyroid disease can affect bones and calcium balance indirectly. Overactive thyroid disease can increase bone turnover and contribute to bone loss over time. Underactive thyroid disease may be linked with low ALP in some cases.
See Thyroid Blood Test Results Explained.
Private calcium and bone profile tests: what to check
Private calcium and bone profile tests can be useful, especially if they include clear markers and proper interpretation. But they can also create confusion if results are flagged without explanation.
If you have a private bone profile result, check:
- whether total calcium and adjusted calcium are both shown
- whether albumin is included
- whether phosphate and ALP are included
- whether vitamin D was actually tested or only assumed
- whether PTH was tested if calcium was abnormal
- whether kidney and liver function were checked
- whether the sample was processed correctly
- whether the laboratory reference ranges are shown
- whether a clinician reviewed the result
Do not start high-dose calcium, vitamin D, magnesium or phosphate supplements based only on a private test report unless a qualified clinician has advised you. Supplements can be harmful in the wrong situation, especially if calcium is high, kidney function is reduced, or you are taking medicines that affect mineral balance.
If your private result is abnormal and you are unsure what to do, see What to Do After Abnormal Private Blood Test Results.
When to contact your GP
Contact your GP or clinician if:
- adjusted calcium is high or low
- calcium is repeatedly abnormal
- ALP is raised and unexplained
- phosphate is significantly abnormal
- albumin is low without an obvious reason
- you have kidney stones, bone pain or unexplained fractures
- you have persistent muscle cramps, tingling or weakness
- you have abnormal kidney or liver results
- you have symptoms such as weight loss, night sweats, fever or severe fatigue
- you are taking calcium or vitamin D supplements and calcium is high
When to seek urgent help
Seek urgent medical help if abnormal calcium is linked with confusion, drowsiness, severe dehydration, repeated vomiting, severe abdominal pain, seizures, fainting, chest pain, irregular heartbeat or severe weakness.
If symptoms include severe cramps, numbness, spasms, seizures or heart rhythm symptoms, low calcium may also need urgent assessment.
How to read your calcium and bone profile results step by step
If you have your report in front of you, use this order rather than focusing on one flagged result.
- Check adjusted calcium first. It is often more useful than total calcium when albumin is abnormal.
- Check albumin. Low albumin can make total calcium look low.
- Check whether calcium is mildly or significantly abnormal. Very high or very low calcium needs faster review.
- Check phosphate. Calcium and phosphate are linked through vitamin D, PTH and kidney function.
- Check ALP. If ALP is raised, ask whether it may be from bone or liver.
- Look at kidney function. eGFR, creatinine and U&E results can change interpretation.
- Look at liver tests. GGT, ALT, AST and bilirubin help interpret ALP and albumin.
- Ask whether vitamin D, PTH or magnesium are needed. These are often separate tests.
- Consider symptoms. Bone pain, kidney stones, cramps, tingling, fatigue, weight loss and confusion matter.
- Check trends. A stable mild abnormality may be different from a new or worsening result.
For wider support interpreting blood reports, see How to Understand Medical Test Results.
The bottom line is that a calcium and bone profile blood test is a useful starting point, not a final diagnosis. It can show mineral imbalance, suggest bone or liver-related patterns, and point towards conditions involving vitamin D, parathyroid hormone, kidneys or bones. But abnormal results need context, and normal results do not rule out every bone condition.
If your result is abnormal, ask what the pattern means, whether it should be repeated, and whether follow-up tests such as vitamin D, PTH, magnesium, kidney function, liver tests or a bone density scan are needed.
Frequently asked questions
What is included in a bone profile blood test?
A standard bone profile commonly includes calcium, adjusted calcium, albumin, phosphate and alkaline phosphatase. Some laboratories may also include total protein or globulins. Vitamin D, magnesium and parathyroid hormone are often separate tests.
What is adjusted calcium?
Adjusted calcium, also called corrected calcium, is calcium adjusted for albumin level. It helps estimate calcium more accurately when albumin is abnormal.
Is adjusted calcium more important than total calcium?
Often, yes. Total calcium can be affected by albumin. Adjusted calcium may give a better estimate in routine testing, although some situations require specialist interpretation or ionised calcium testing.
What does high calcium mean?
High calcium may be linked with primary hyperparathyroidism, supplements, dehydration, medicines, kidney disease or less commonly cancer-related causes. It needs interpretation with PTH, vitamin D, kidney function and symptoms.
What does low calcium mean?
Low calcium may be linked with low albumin, vitamin D deficiency, low parathyroid hormone, kidney disease, magnesium deficiency or other conditions. Adjusted calcium helps show whether calcium is truly low.
Can low albumin make calcium look low?
Yes. Because some calcium is bound to albumin, low albumin can make total calcium appear low. Adjusted calcium is used to account for this.
What does high phosphate mean?
High phosphate may be linked with kidney disease, low parathyroid hormone, excess phosphate intake, cell breakdown or other metabolic problems. It should be interpreted with calcium, kidney function, vitamin D and PTH.
What does low phosphate mean?
Low phosphate may be caused by vitamin D deficiency, overactive parathyroid glands, poor nutrition, alcohol-related illness, refeeding, some medicines or other conditions.
What does high ALP mean in a bone profile?
High ALP can come from bone or liver. It may be linked with liver or bile duct problems, vitamin D deficiency, Paget’s disease, healing fracture, pregnancy, growth in children or other conditions.
How do doctors know if ALP is from bone or liver?
They often check GGT and other liver tests. If ALP and GGT are both raised, a liver or bile duct source may be more likely. If ALP is raised with normal liver markers, bone causes may be considered.
Does a bone profile test for osteoporosis?
No. A bone profile does not diagnose osteoporosis. Osteoporosis is usually assessed with a DEXA bone density scan. Blood tests can help look for causes that affect bone health.
Does a bone profile include vitamin D?
Not always. Vitamin D is often a separate test and may not be included in a standard bone profile unless specifically requested.
Does a bone profile include PTH?
Usually no. Parathyroid hormone is often requested separately when calcium is abnormal or parathyroid disease is suspected.
Can vitamin D deficiency affect bone profile results?
Yes. Vitamin D deficiency can contribute to low calcium, low phosphate and raised ALP in some people, especially when deficiency is significant.
Can kidney disease affect calcium and phosphate?
Yes. The kidneys help regulate phosphate, vitamin D activation and mineral balance. Kidney disease can affect calcium, phosphate and parathyroid hormone levels.
Can thyroid problems affect bone health?
Yes. Overactive thyroid disease can increase bone turnover and contribute to bone loss over time. Thyroid tests may be checked if symptoms or risk factors suggest thyroid disease.
Should I take calcium if my calcium is low?
Not without advice. Low calcium may have different causes, and treatment depends on adjusted calcium, vitamin D, magnesium, kidney function and PTH. Taking calcium when it is not appropriate can be harmful.
Should I stop vitamin D if calcium is high?
Do not stop prescribed treatment without medical advice, but tell your GP if calcium is high and you take vitamin D or calcium supplements. Your dose and blood results may need review.
When is high calcium urgent?
High calcium may be urgent if it is very high or linked with confusion, dehydration, repeated vomiting, severe weakness, severe abdominal pain, irregular heartbeat or feeling very unwell.
What should I do after an abnormal private bone profile?
Check adjusted calcium, albumin, phosphate, ALP, kidney and liver results. Share the full report with your GP if results are significantly abnormal, repeated, unexplained or linked with symptoms.
