Calcium, Ionized
The bioavailable fraction of calcium, more accurate than total calcium when albumin is abnormal.
Consider this test if:
- Total calcium came back borderline or did not match your symptoms
- Working up suspected hyperparathyroidism or a parathyroid abnormality
- Low albumin, liver disease, or kidney disease that can skew total calcium
- Symptoms of calcium imbalance: numbness, tingling, muscle cramps, fatigue, or kidney stones
- Following a known calcium or parathyroid disorder over time
- HSA/FSA eligible
- Typical results in 1-2 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting is generally required. The sample handling matters more than prep: the tube must stay sealed because exposure to air shifts pH and can make the ionized calcium unmeasurable, so this is drawn as a dedicated, unopened tube. A morning draw is standard.
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What this test is for
Ionized calcium is the free, biologically active calcium circulating in the blood, the fraction your nerves, muscles, and bones actually use. Most calcium in the blood is bound to albumin, so total calcium can read normal or abnormal simply because protein levels shifted; ionized calcium measures the active portion directly and cuts through that distortion. It is the more reliable number when total calcium does not fit the clinical picture, as in primary hyperparathyroidism, low albumin, kidney disease, or acid-base disturbances. Abnormal results connect to symptoms across several systems: high calcium with fatigue, excessive thirst, constipation, kidney stones, or bone pain, and low calcium with numbness, tingling, muscle cramps, or spasms.
This is the specialized form. Routine screening uses the total calcium test, which is fine for most people; ionized calcium is the right choice when albumin is off, when total calcium is borderline, or when a parathyroid or calcium-regulation question needs a direct answer.
- Specimen
- Serum or plasma
- Method
- Ion-selective electrode
- Measures
- Mass concentration
What you'll learn
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Insights that connect the dots. A clinician reads your whole picture, not one result in isolation, connecting family history, past results, and lifestyle into clear next steps.
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Your personalized action plan. Nutrition, supplements, and training in one clinician-reviewed protocol, updated as your results change.
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Track your trends. Upload results from any lab and see each biomarker trend over time, so you know what is working.
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Never miss a recheck. Mito tells you what is worth retesting and when, then reminds you so nothing slips.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in 1-2 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
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Without membership
$0
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost, covering the lab and what it takes to run the service. It is never a profit on the test itself. Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9 per month, and any applicable lab order or draw fee is itemized before you pay.
Where do I get tested?
Choose an available partner lab at checkout. If your cart contains multiple blood tests, Mito helps consolidate the eligible tests at one lab when possible. At-home kits and scans follow the collection or appointment process shown on their product page.
Is this eligible for HSA/FSA?
Yes. Eligible tests can be paid for with an HSA or FSA card at checkout.
When will I get my results?
Your results appear in your Mito dashboard after the laboratory completes processing. A clinician then reviews them before your analysis and personalized action plan are finalized. Timing varies by test, and specialty assays and at-home kits may take longer.
Do I need a physician's order?
No. Mito provides the laboratory order when one is required, so you do not need to arrange a separate physician visit before purchasing.
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