Post-Thyroidectomy Hypoparathyroidism TreatmentNCT07577570
Calcium Replacement Therapy in Postoperative Hypoparathyroidism
A study testing Calcium carbonate 1250 mg (500 mg elemental calcium) twice a day and Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a day in people with Post-Thyroidectomy Hypoparathyroidism Treatment, run by Tartu University Hospital at 2 sites in Estonia.
Trial summary
The goal of this clinical trial is to evaluate whether a lower-dose calcium replacement therapy is non-inferior to a higher-dose regimen in preventing symptomatic hypoparathyroidism in patients following thyroidectomy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Post-Thyroidectomy Hypoparathyroidism Treatment
- What is being tested?
- Calcium carbonate 1250 mg (500 mg elemental calcium) twice a day and Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a day
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 2 sitesEstonia
- Study dates
- 18 Nov 2025to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- patients over the age of 18 undergoing surgery involving both lobes of the thyroid gland (thyroidectomy, "near-total" thyroidectomy, subtotal thyroidectomy, and "completed" thyroidectomy)
- Based on the first post-operative day analysis, PTH levels are below the normal range (in our hospitals 1.8-7.8 pmol/l), but not so low (below 1.06 pmol/L) as to require calcium replacement therapy with calcitriol (rocaltrol)
Who cannot join
- previously diagnosed osteoporosis; the patient is already taking calcium and vitamin D supplements prior to thyroid surgery
- renal insufficiency (eGFR < 30)
- patients with concomitant hyperparathyroidism undergoing simultaneous thyroidectomy and parathyroidectomy for a parathyroid adenoma
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Ceith Nikkolo contact
Estonia2 sites, 2 recruiting
- Recruiting
East Tallinn Central Hospital
Tallinn, Other, 11914
Hanna Hollman, MD, + 372 59037517, hanna.hollman@itk.ee
- Recruiting
Tartu University Hospital
Tartu
Ceith Nikkolo, PhD, +372 53319082, ceith.nikkolo@kliinikum.ee
About this study
Official title: A Pilot Study of Calcium Replacement Therapy in Postoperative Hypoparathyroidism
The goal of this clinical trial is to evaluate whether a lower-dose calcium replacement therapy is non-inferior to a higher-dose regimen in preventing symptomatic hypoparathyroidism in patients following thyroidectomy. The hypothesis is:
- lower-dose calcium replacement therapy is non-inferior to higher-dose therapy in preventing symptomatic hypoparathyroidism during the first two postoperative weeks
Read more
Researchers will compare patients receiving a lower-dose calcium replacement regimen with those receiving a higher-dose regimen to assess whether the lower dose is not associated with a higher incidence of symptomatic hypoparathyroidism.
Patients who develop post-thyroidectomy hypoparathyroidism are divided into groups for calcium replacement therapy. If they are asymptomatic, they will be scheduled for a follow-up visit at two weeks after surgery. During the follow-up visit, calcium metabolism will be evaluated, and treatment adjusted if necessary.
- Being tested
- Calcium carbonate 1250 mg (500 mg elemental calcium) twice a day, Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a day
- Keywords
- thyroidectomy, calcium replacement therapy, postoperative hypoparathyroidism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Calcium carbonate 1250 mg (500 mg elemental calcium) twice a dayDrug
One study group takes calcium carbonate 1250 mg (500 mg elemental calcium) twice a day (at lunchtime and in the evening)
Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a dayDrug
The second study group takes 1250 mg of calcium carbonate (500 mg of elemental calcium) four times a day (starting at noon, at approximately 4-hour intervals: at noon, in the early afternoon, in the evening, and before bedtime). This dosage regimen is prescribed because 500 mg of calcium can be absorbed at a time.
| Study group | Role | What they receive |
|---|---|---|
| Lower dose calcium replacement | Active comparator | calcium carbonate 1250 mg x 2 Receives: Drug: Calcium carbonate 1250 mg (500 mg elemental calcium) twice a day |
| Higher dose calcium replacement | Active comparator | calcium carbonate 1250 mg x 4 Receives: Drug: Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a day |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurence of symptomatic hypoparathyroidism
Occurrence of symptomatic hypoparathyroidism within 14 days postoperatively
Measured: 2 weeks
Secondary outcomes (3)
Serum calcium levels at 2 week follow-up
Comparison of serum calcium levels at the 2-week follow-up between lower- and higher-dose calcium replacement groups.
Measured: 2 weeks
Duration and permanence of hypoparathyroidism
Assessment of whether postoperative hypoparathyroidism resolves (transient) or persists (permanent) during follow-up.
Measured: Up to 12 months postoperatively
Serum parathyroid hormone (PTH) levels at 2 week follow-up
Comparison of serum parathyroid hormone (PTH) levels at the 2-week follow-up between lower- and higher-dose calcium replacement groups.
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 May 2026
- Study start18 Nov 2025
- Primary completionOct 2027 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Post-Thyroidectomy Hypoparathyroidism TreatmentStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- This study evaluates different dosing regimens of a widely used calcium preparation; as the drug is already approved and commonly used, a clinical trial phase is not applicable
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tartu University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- East Tallinn Central Hospital
- Responsible party
- Principal investigator, Ceith Nikkolo, Tartu University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07577570
- Sponsor's protocol ID
- TartuUH-ETCH_403/T-13_2
- Status last verified
- May 2026
- First submitted
- 21 Apr 2026
- Last updated
- 11 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study of Calcium Replacement Therapy in Postoperative Hypoparathyroidism
- ClinicalTrials.gov ID
- NCT07577570
- Acronym / sponsor ID
- TartuUH-ETCH_403/T-13_2
- Keywords
- thyroidectomy, calcium replacement therapy, postoperative hypoparathyroidism
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Tartu University HospitalUniversity, hospital or other
- Collaborators
- East Tallinn Central Hospital
- Study start
- 18 Nov 2025 (actual)
- Primary completion
- Oct 2027 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 11 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to evaluate whether a lower-dose calcium replacement therapy is non-inferior to a higher-dose regimen in preventing symptomatic hypoparathyroidism in patients following thyroidectomy. The hypothesis is:
- lower-dose calcium replacement therapy is non-inferior to higher-dose therapy in preventing symptomatic hypoparathyroidism during the first two postoperative weeks
Researchers will compare patients receiving a lower-dose calcium replacement regimen with those receiving a higher-dose regimen to assess whether the lower dose is not associated with a higher incidence of symptomatic hypoparathyroidism.
Patients who develop post-thyroidectomy hypoparathyroidism are divided into groups for calcium replacement therapy. If they are asymptomatic, they will be scheduled for a follow-up visit at two weeks after surgery. During the follow-up visit, calcium metabolism will be evaluated, and treatment adjusted if necessary.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- This study evaluates different dosing regimens of a widely used calcium preparation; as the drug is already approved and commonly used, a clinical trial phase is not applicable
| Arm | Type | Receives |
|---|---|---|
| Lower dose calcium replacement | Active comparator | Drug: Calcium carbonate 1250 mg (500 mg elemental calcium) twice a daycalcium carbonate 1250 mg x 2 |
| Higher dose calcium replacement | Active comparator | Drug: Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a daycalcium carbonate 1250 mg x 4 |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- patients over the age of 18 undergoing surgery involving both lobes of the thyroid gland (thyroidectomy, "near-total" thyroidectomy, subtotal thyroidectomy, and "completed" thyroidectomy)
- Based on the first post-operative day analysis, PTH levels are below the normal range (in our hospitals 1.8-7.8 pmol/l), but not so low (below 1.06 pmol/L) as to require calcium replacement therapy with calcitriol (rocaltrol)
Key exclusion criteria (3 listed)
- previously diagnosed osteoporosis; the patient is already taking calcium and vitamin D supplements prior to thyroid surgery
- renal insufficiency (eGFR < 30)
- patients with concomitant hyperparathyroidism undergoing simultaneous thyroidectomy and parathyroidectomy for a parathyroid adenoma
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Calcium carbonate 1250 mg (500 mg elemental calcium) twice a dayOne study group takes calcium carbonate 1250 mg (500 mg elemental calcium) twice a day (at lunchtime and in the evening) | Drug | Lower dose calcium replacement |
| Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a dayThe second study group takes 1250 mg of calcium carbonate (500 mg of elemental calcium) four times a day (starting at noon, at approximately 4-hour intervals: at noon, in the early afternoon, in the evening, and before bedtime). This dosage regimen is prescribed because 500 mg of calcium can be absorbed at a time. | Drug | Higher dose calcium replacement |
Primary outcome
Occurence of symptomatic hypoparathyroidism
Time frame: 2 weeks
Occurrence of symptomatic hypoparathyroidism within 14 days postoperatively
3 secondary outcomes
Serum calcium levels at 2 week follow-up
Time frame: 2 weeks
Duration and permanence of hypoparathyroidism
Time frame: Up to 12 months postoperatively
Serum parathyroid hormone (PTH) levels at 2 week follow-up
Time frame: 2 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 May 2026.
- Individual participant dataSharing planned: Undecided
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ceith Nikkolo contact
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Calcium carbonate 1250 mg (500 mg elemental calcium) twice a day and Calcium carbonate 1250 mg (500 mg elemental calcium) 4 times a day in people with Post-Thyroidectomy Hypoparathyroidism Treatment, run by Tartu University Hospital at 2 sites in Estonia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Estonia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Hanna Hollman (+37259037517, hanna.hollman@ut.ee), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Occurence of symptomatic hypoparathyroidism (time frame: 2 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 May 2026.