Medically reviewed by Dr. Farhana Mukhtar, M.B.B.S., M.Phil (Pb.), Consultant Chemical Pathologist, Al-Nasar Lab & Diagnostic Centre. Updated October 2026.
Quick answer: A bone profile measures calcium, albumin, phosphate and alkaline phosphatase, usually alongside vitamin D. The single most important point: calcium must be corrected for albumin, because about half the calcium in blood is carried bound to that protein. A low albumin produces a low calcium reading in someone whose actual calcium is perfectly normal.
Book a bone profile: call 0300 0341944, or arrange home sample collection across Lahore on 0309 1166944.
What the bone profile measures
| Test | What it shows | Typical adult range |
|---|---|---|
| Total calcium | All calcium in blood, bound and free | roughly 8.5 to 10.5 mg/dL |
| Albumin | The protein carrying about half the calcium. Essential for interpretation | roughly 3.5 to 5.0 g/dL |
| Corrected calcium | Calcium adjusted for albumin. The value that actually matters | roughly 8.5 to 10.5 mg/dL |
| Phosphate | Works with calcium. Affected by kidney function | roughly 2.5 to 4.5 mg/dL |
| Alkaline phosphatase | Bone turnover. Also rises in liver disease | roughly 40 to 130 U/L |
| Vitamin D | Whether calcium can be absorbed at all | 30 ng/mL and above is generally adequate |
| PTH | Parathyroid hormone, the body’s calcium controller | added when calcium is abnormal |
Ranges differ between laboratories, so read the range on your own report.
Why corrected calcium is the number that counts
Roughly half the calcium in your blood travels bound to albumin and is biologically inactive. The other half is free and is what the body actually uses.
A standard test measures total calcium, both fractions together. So anything that changes albumin changes the total calcium reading without changing the amount of active calcium at all.
This matters in practice because low albumin is common: in liver disease, kidney disease, malnutrition, and in anyone significantly unwell. Those patients routinely show a low total calcium while their corrected calcium is entirely normal.
If your report shows a low calcium, look for the albumin and the corrected value before concluding anything. If corrected calcium is not reported, ask for it.
Why vitamin D comes before calcium supplements
This is the most useful practical point for most people in Pakistan.
Vitamin D is what allows the gut to absorb calcium. Without enough of it, dietary calcium largely passes through unabsorbed no matter how much you take.
Vitamin D deficiency is extremely common here, including in sunny cities, because of indoor lifestyles, covering clothing, air pollution reducing UV penetration, and darker skin requiring longer exposure to produce the same amount.
The result is a familiar pattern: someone with body aches and fatigue starts calcium tablets, feels no better, and increases the dose. The problem was never calcium intake. It was absorption.
Correct the vitamin D first. Calcium supplementation without adequate vitamin D is largely wasted, and unnecessary long term calcium supplements carry their own risks, including kidney stones.
What causes high calcium?
High corrected calcium is less common than low, and it is more likely to be significant. Two causes account for the large majority.
- Overactive parathyroid gland. Usually a small benign growth on one of the four parathyroid glands, producing too much hormone. Often found incidentally and curable with minor surgery
- Cancer. Certain cancers raise calcium, either by spreading to bone or by producing hormone like substances
Less common causes include excessive vitamin D or calcium supplementation, thiazide diuretics, lithium, overactive thyroid and sarcoidosis.
Symptoms are vague and easily attributed to other things: tiredness, low mood, constipation, excessive thirst, frequent urination, abdominal pain, kidney stones and bone pain.
A persistently raised corrected calcium should never be ignored. The next step is usually a PTH level, which neatly separates the two main causes: high or inappropriately normal PTH points to the parathyroid gland, while a suppressed PTH points elsewhere and needs investigation.
What causes low calcium?
- Vitamin D deficiency, by far the most common
- Low albumin, which is an artefact rather than true low calcium
- Chronic kidney disease, which impairs the activation of vitamin D
- Underactive parathyroid glands, often after thyroid surgery
- Low magnesium, which must be corrected before calcium will respond
- Malabsorption, including coeliac disease
- Certain medicines
Symptoms of genuinely low calcium include tingling around the mouth and in the fingers, muscle cramps and spasms.
Who should be tested?
- Persistent bone pain, body aches or muscle weakness
- A fracture from a minor fall, which suggests weak bone
- Known or suspected osteoporosis, usually alongside a DEXA bone density scan
- Postmenopausal women, in whom bone loss accelerates
- Anyone with chronic kidney disease, as a routine part of monitoring
- Recurrent kidney stones
- Unexplained tiredness, constipation or excessive thirst
- Before and after thyroid or parathyroid surgery
- People on long term steroids, anticonvulsants or diuretics
- Anyone already taking calcium or vitamin D supplements, to check they are appropriate
How to prepare
- Fasting for 8 to 12 hours is usually advised, as recent food affects phosphate in particular
- Stop calcium and vitamin D supplements for 24 hours beforehand unless your doctor says otherwise, since a recent dose distorts the result
- A morning sample is preferred, especially if PTH is included, as PTH varies through the day
- Avoid a prolonged tourniquet during the blood draw, which can falsely raise calcium. Mention it if the draw was difficult
- Bring a list of your medicines, particularly diuretics, lithium, steroids and antacids
- Ask for albumin to be included so corrected calcium can be calculated
Bone profile testing at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre has provided laboratory and imaging services in Lahore since 1996 and holds ISO 15189:2022 accreditation from the Pakistan National Accreditation Council. Calcium, albumin, phosphate, alkaline phosphatase, vitamin D and PTH are all available from one sample, with home sample collection across Lahore.
Because bone health needs both blood results and bone density, DEXA scanning is available on the same Johar Town campus and the two are commonly done together.
See our accreditations, find your nearest collection centre, or contact us to book.
Frequently Asked Questions
What is corrected calcium?
Calcium adjusted for the albumin level. Since about half of blood calcium is carried on albumin, a low albumin gives a falsely low total calcium. The corrected value is the meaningful one.
Do I need to fast for a calcium test?
Fasting for 8 to 12 hours is usually advised, and supplements should generally be paused for 24 hours beforehand.
Should I take calcium tablets for body aches?
Not without testing. Vitamin D deficiency is the far more common cause here, and calcium cannot be absorbed properly without it. Correct the vitamin D first.
What does a high calcium level mean?
Most often an overactive parathyroid gland, sometimes cancer. A persistently raised corrected calcium needs investigation, usually starting with a PTH level.
Is a low calcium result always a problem?
No. A low albumin produces a low total calcium in someone whose active calcium is normal. Check the corrected value before concluding anything.
This article is for general information and is not a substitute for medical advice. Please discuss your results with a qualified doctor.
