A Phase 2 interventional study of Ergocalciferol 50,000 IU and Methimazole in Graves Disease, Graves' Disease and Hyperthyroidism, sponsored by Northwell Health. Active, not recruiting at 1 site in United States. Open to participants aged 9 Years to 17 Years. Per ClinicalTrials.gov, last updated 2026-10-23.
Sponsored by Northwell Health · Phase 2, Interventional, and Other
The goal of this randomized pilot feasibility clinical trial is to determine the feasibility of implementing a protocol for a larger trial to assess the effects of high-dose vitamin D supplementation in pediatric patients (9-17 years old) newly diagnosed with Graves' disease. The main questions it aims to answer are:
What are the recruitment and adherence rates for a larger trial using this protocol? Is the data collection process complete and robust enough for a larger trial? What are the potential barriers to implementing a larger-scale trial? Researchers will compare vitamin D supplementation plus standard methimazole therapy to methimazole therapy alone (with participants permitted to take up to 1000 International Units of vitamin D2 daily) to explore potential effects on thyroid hormone and antibody levels.
Participants will:
Be randomized to either the intervention or control group. Take study medications (vitamin D or placebo) as directed. Attend regular study visits for blood tests and clinical assessments. Complete medication logs.
This pilot feasibility study will evaluate the practicality of conducting a larger randomized controlled trial (RCT) investigating the impact of high-dose vitamin D2 (ergocalciferol) supplementation as an adjunctive therapy to standard methimazole treatment in pediatric patients aged 9-17 years newly diagnosed with Graves' disease (GD). This study aims to address the current gap in research regarding vitamin D supplementation's effect on antibody and thyroid hormone trends in this population. Specifically, the study will examine the feasibility of recruitment, adherence to the intervention regimen, completeness of data collection, and any potential barriers to implementing a larger-scale trial.
The rationale for this study stems from the observed association between low vitamin D levels and an increased risk of Graves' disease, coupled with the limited data on vitamin D supplementation's influence on disease progression in children. This pilot study will investigate whether high-dose vitamin D supplementation, alongside methimazole, affects Thyroid Receptor Antibody (TRAb) and Thyroid Stimulating Immunoglobulin (TSI) antibody levels, as well as thyroid hormone levels (Total T3, Free Thyroxine, Total Thyroxine, TSH), in newly diagnosed pediatric GD patients.
Participants will be randomized 1:1 to either an intervention arm (methimazole + high-dose vitamin D2) or a control arm (methimazole only, with the option of taking up to 1000 IU/day of vitamin D2). The intervention arm will receive 50,000 IU of vitamin D2 weekly for 8 weeks, followed by 50,000 IU every two weeks for 16 weeks, along with standard methimazole therapy as directed by their treating endocrinologist. The control arm will receive standard methimazole therapy alone, per their physician's orders, with the option of taking up to 1000 IU of Over-the-counter (OTC) vitamin D2 daily, if desired. The study will not provide this OTC vitamin D.
The primary feasibility outcomes will be: (1) recruitment rate; (2) adherence rate to the vitamin D supplementation, assessed through pill counts, medication logs, and self-report; (3) data completeness; and (4) identification of any barriers encountered during study implementation. Exploratory clinical outcomes will include time to normalization of thyroid function tests and the percentage change from baseline in TRAb and TSI antibody levels at 24 weeks. Safety and tolerability will be closely monitored, with particular attention to hypercalcemia and hypervitaminosis D. Data on adverse events will be collected and graded using the CTCAE v5.0.
Data analysis will primarily focus on descriptive statistics for feasibility outcomes. Exploratory clinical outcomes will be analyzed to estimate effect sizes and variability, informing the design of a future, adequately powered RCT. This pilot study is not powered to detect statistically significant differences in clinical outcomes.
This study will provide critical preliminary data and feasibility metrics to inform the development of a larger, more definitive RCT evaluating vitamin D's efficacy as an adjunctive therapy in pediatric Graves' disease. This research has the potential to significantly advance our understanding of the role of vitamin D in autoimmune thyroid disease and contribute to improved treatment strategies for children with Graves' disease.
The FDA has granted an Investigational New Drug (IND) exemption (PIND 176865, dated April 30, 2025) for this pilot feasibility study evaluating high-dose vitamin D2 in children with Graves' disease. The exemption allows the study to proceed without a full IND application.
162 studies on the registry are indexed under Graves Disease; 53 are open to participants now.
This study's planned enrollment of 30 is below the median of 60 across 104 interventional studies indexed under Graves Disease.
Browse Graves Disease studies →Northwell Health is the lead sponsor of 475 studies on the registry; 107 are open to participants now.
Of its 45 completed or terminated interventional studies of FDA-regulated products, 23 (51%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this arm will receive methimazole at a dose determined by their treating physician, according to standard clinical practice guidelines for pediatric Graves' disease. In addition, they will receive high-dose vitamin D2 (ergocalciferol) 50,000 IU orally weekly for the first 8 weeks, followed by 50,000 IU orally every two weeks for the remaining 16 weeks of the study.
Drug: Ergocalciferol 50,000 IU · Drug: Methimazole
Participants in this arm will receive methimazole at a dose determined by their treating physician, according to standard clinical practice guidelines for pediatric Graves' disease. Participants will have the option of taking up to 1000 IU of vitamin D2 daily, purchased over-the-counter, but this will not be provided by the study. This is to address potential vitamin D deficiency while maintaining a comparison group.
Drug: Methimazole
Participants will receive ergocalciferol 50,000 IU oral capsules weekly for the first 8 weeks, followed by 50,000 IU every two weeks for the subsequent 16 weeks (total 24 weeks).
Methimazole is considered standard of care for pediatric Graves' disease. Dosing is determined and adjusted by the participant's treating physician
Feasibility Metrics: Recruitment Rate
Percentage of eligible participants approached who consent to participate in the study. This metric will assess the efficiency of recruitment strategies.
Time frame: through study completion, an average of 1 yea
Feasibility Metrics: Adherence Rate
Percentage of prescribed vitamin D doses taken by participants in the intervention arm. Adherence will be tracked via pill counts and participant self-report.
Time frame: From enrollment to 24 week/6month follow up visit
Feasibility Metrics: Data Completeness
Percentage of completed data fields for key outcome measures (thyroid function tests, TSI levels, etc.). This will assess the quality and completeness of data collection.
Time frame: From baseline data collection to the 24-week/6-month follow-up visit.
Feasibility Metrics: Implementation Barriers
A qualitative assessment of any challenges encountered during the study implementation (e.g., recruitment difficulties, adherence issues, logistical problems). This assessment will inform strategies for overcoming these barriers in a future, larger-scale RCT.
Time frame: through study completion, an average of 1 year
Time to Normalization and Thyroid function Trends
We hypothesize that patients receiving high-dose vitamin D will achieve normal TSH, T3, Free T4 and T4 levels significantly faster than those receiving methimazole alone. Thyroid function tests will be measured at baseline, 6, 12 and 24 weeks, and time to normalization will be compared between groups.
Time frame: from enrollment to 24 week/6month follow up visit
Change in TRAb and TSI Levels
We hypothesize that patients receiving high-dose vitamin D will experience a significantly greater percentage reduction in TSH R-Ab and TSI levels at 24 weeks compared to those receiving methimazole alone. Antibody levels will be measured at baseline and 24 weeks, and the percentage change from baseline will be compared between groups.
Time frame: from enrollment to 24 week/6month visit
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — Individual participant data from this pilot feasibility study will not be shared immediately due to the small sample size and the increased risk of participant re-identification. However, data sharing aligned with journal requirements will be considered upon publication of the study results. A detailed data sharing plan will be developed at that time, addressing ethical considerations and ensuring participant privacy while maximizing the scientific value of the data. This plan will outline the specific data to be shared (e.g., de-identified data, specific variables) and the process for requesting access.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Data sharing will be considered upon acceptance of the manuscript for publication in a peer-reviewed journal.
Access criteria: Researchers may request access to the de-identified individual participant data by contacting Dr Sharon Hyman or Dr Sofya Ilmer. Requests will be reviewed based on scientific merit, adherence to data use agreements, and capacity to protect participant confidentiality. A data use agreement will be required. Data will be shared in a format compliant with relevant privacy regulations (e.g., HIPAA).
Started Aug 2025 (actual). Primary completion is estimated for Oct 2026, 14 months after the start.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 23, 2026: primary completion Feb 2027 → Oct 2026 and completion Feb 2027 → Oct 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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