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Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 2INTERVENTIONAL

Zinc Supplementation in Sickle Cell Disease: A Precursor to the Think Zinc for Bones Trial

Zinc Supplementation in Sickle Cell Disease: A Precursor to the Think Zinc for Bones Trial (NCT06260891) is a Phase 2 interventional studying Sickle Cell Disease, sponsored by University of California, San Francisco. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

Important: This information is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

About This Trial

The goal of this short term prospective Phase II study is to compare the effects of two alternate daily doses of zinc (25 and 40 mg/day) in 34 randomly assigned homozygous Sickle Cell Disease (SCD-SS) patients aged 15-40 years old. The main question it aims to answer is: Which biomarkers are most responsive to zinc supplementation, and what is the maximum tolerated zinc dose that induces the desired changes in biomarkers of bone turnover? Participants will be recruited from 6 American Society Hematology Research Collaborative SCD Centers. Eligible SCD subjects will be invited to participate in the 16-week study, involving 2 baseline blood draws 4 weeks apart, followed by a 12-week zinc intervention. The findings from this study will be used to determine the dosage of zinc to be used in a larger, future study on the long term impact of zinc supplementation on bone health in SCD-SS.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Sickle Cell Disease and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 34 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - Age: ≥ 15.0 to ≤ 40.0 years - Diagnosis: SCD-SS or SCD-S Beta zero Thalassemia, in steady state (defined as a minimum of 2 weeks days following pain crisis) - Male or Female Who Should NOT Join This Trial: - Taking any supplement containing zinc and unable/willing to stop for 3 months prior to study start - 25-Hydroxy Vitamin D \< 20 ng/mL - On chronic transfusion therapy (defined as \>8 Transfusions/year) and iron overloaded (defined as liver iron concentration \> 7 mg/g OR average serum ferritin \>4000 ug/L) - Unable swallow pills or take daily supplement as instructed - Currently participating in another investigational drug trial - Prior diagnosis of chronic kidney disease (eGFR \< 30 mL/min/1.73m2) Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language
Inclusion Criteria: * Age: ≥ 15.0 to ≤ 40.0 years * Diagnosis: SCD-SS or SCD-S Beta zero Thalassemia, in steady state (defined as a minimum of 2 weeks days following pain crisis) * Male or Female Exclusion Criteria: * Taking any supplement containing zinc and unable/willing to stop for 3 months prior to study start * 25-Hydroxy Vitamin D \< 20 ng/mL * On chronic transfusion therapy (defined as \>8 Transfusions/year) and iron overloaded (defined as liver iron concentration \> 7 mg/g OR average serum ferritin \>4000 ug/L) * Unable swallow pills or take daily supplement as instructed * Currently participating in another investigational drug trial * Prior diagnosis of chronic kidney disease (eGFR \< 30 mL/min/1.73m2)

Treatments Being Tested

DRUG

25 mg/day zinc

25 mg of zinc as zinc gluconate taken orally once a day

DRUG

40 mg/day zinc

40 mg of zinc as zinc gluconate taken orally once a day

Locations (6)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

UCSF Benioff Children's Hospital Oakland
Oakland, California, United States
Duke University Medical Center
Durham, North Carolina, United States
Cincinnati Children's Hospital
Cincinnati, Ohio, United States
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, United States
Thomas Jefferson University Hospital
Philadelphia, Pennsylvania, United States
Baylor College of Medicine
Houston, Texas, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06260891), the sponsor (University of California, San Francisco), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06260891 clinical trial studying?

The goal of this short term prospective Phase II study is to compare the effects of two alternate daily doses of zinc (25 and 40 mg/day) in 34 randomly assigned homozygous Sickle Cell Disease (SCD-SS) patients aged 15-40 years old. The main question it aims to answer is: Which biomarkers are most responsive to zinc supplementation, and what is the maximum tolerated zinc dose that induces the desired changes in biomarkers of bone turnover? Participants will be recruited from 6 American Society Hematology Research Collaborative SCD Centers. Eligible SCD subjects will be invited to participate in… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06260891?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06260891?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06260891. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06260891. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.