NCT06260891 · University of California, San Francisco
Zinc Supplementation in Sickle Cell Disease: A Precursor to the Think Zinc for Bones Trial
(ZnSCD)
What this study is about
The goal of this short term forward-looking 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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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)
Where
- Oakland, California
- Durham, North Carolina
- Cincinnati, Ohio
- Philadelphia, Pennsylvania
- Houston, Texas
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 13, 2026 · Source of record for eligibility and locations