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ClinicalTrials.gov public records Last synced Nov 14, 2026, 9:35 PM EST

All trial information on this site comes from the official ClinicalTrials.gov public API (clinicaltrials.gov/api/v2), run by the U.S. National Library of Medicine. We only display that public information; we do not add opinions, endorsements, or any other intent. Always review the official ClinicalTrials.gov record for the latest information.

Showing 25–48 of 121 matching trials from the live ClinicalTrials.gov search.

Filters: Intervention: Vitamin D3 - high dose Clear all

Conditions: Breast Neoplasms
Interventions: Vitamin D, Calcium carbonate, Vitamin D, Placebo; Dietary Supplement · Drug · Other
Lead sponsor: Washington University School of Medicine; Other
Eligibility: 18 Years and older · Female only
Enrollment: 63 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2005 – 2009
U.S. locations: 1
States / cities: St Louis, Missouri

Conditions: Breast, Breast Cancer, Osteoporosis
Interventions: High Dose Vitamin D, Standard of Care Vitamin D; Dietary Supplement
Lead sponsor: Wake Forest University Health Sciences; Other
Eligibility: 18 Years to 45 Years · Female only
Enrollment: 7 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2021 – 2024
U.S. locations: 1
States / cities: Charlotte, North Carolina

Conditions: brca1 Mutation Carrier, brca2 Mutation Carrier, Breast Cancer
Interventions: cholecalciferol, placebo; Dietary Supplement · Other
Lead sponsor: SWOG Cancer Research Network; Network
Eligibility: 18 Years to 50 Years · Female only
Enrollment: 208 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2011 – 2017
U.S. locations: 360
States / cities: Anniston, Alabama • Mobile, Alabama • Anchorage, Alaska + 230 more

Conditions: Prostate Adenocarcinoma, Stage I Prostate Cancer, Stage IIA Prostate Cancer, Stage IIB Prostate Cancer
Interventions: Cholecalciferol, Genistein, Laboratory Biomarker Analysis, Pharmacological Study, Placebo; Drug · Other
Lead sponsor: National Cancer Institute (NCI); NIH
Eligibility: 18 Years and older · Male only
Enrollment: 15 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2011 – 2014
U.S. locations: 11
States / cities: Birmingham, Alabama • Baltimore, Maryland • Burlington, Massachusetts + 6 more

Conditions: Stage IV Colon Cancer, Stage IV Rectal Cancer
Interventions: leucovorin calcium, bevacizumab, cholecalciferol, fluorouracil, oxaliplatin, pharmacological study; Drug · Biological · Dietary Supplement + 1 more
Lead sponsor: Roswell Park Cancer Institute; Other
Eligibility: 18 Years to 79 Years
Enrollment: 10 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2010 – 2012
U.S. locations: 1
States / cities: Buffalo, New York

Conditions: Obesity
Interventions: Vitamin D3; Dietary Supplement
Lead sponsor: Mayo Clinic; Other
Eligibility: 12 Years to 18 Years
Enrollment: 51 participants
Healthy volunteers: Accepts healthy volunteers
Timeline: 2009 – 2012
U.S. locations: 1
States / cities: Rochester, Minnesota

Conditions: Atopic Dermatitis, Vitamin D Deficiency
Interventions: Vitamin D; Drug
Lead sponsor: Medical College of Wisconsin; Other
Eligibility: 1 Year to 18 Years
Enrollment: 7 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2010 – 2013
U.S. locations: 1
States / cities: Milwaukee, Wisconsin

Conditions: Neurofibromatosis Type 1 (NF1)
Interventions: Cholecalciferol; Drug
Lead sponsor: University of Utah; Other
Eligibility: 25 Years to 40 Years
Enrollment: 26 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2017 – 2022
U.S. locations: 2
States / cities: Cincinnati, Ohio • Salt Lake City, Utah

Conditions: Vitamin D Deficiency, Falls
Interventions: 200 IU/d cholecalciferol, 1000 IU/d cholecalciferol, 2000 IU/d cholecalciferol, 4000 IU/d cholecalciferol; Dietary Supplement
Lead sponsor: Johns Hopkins University; Other
Eligibility: 70 Years and older
Enrollment: 688 participants
Healthy volunteers: Accepts healthy volunteers
Timeline: 2015 – 2019
U.S. locations: 2
States / cities: Baltimore, Maryland • Hagerstown, Maryland

Conditions: Thalassemia Major
Interventions: Vitamin D3, Placebo; Drug
Lead sponsor: Weill Medical College of Cornell University; Other
Eligibility: 6 Years to 60 Years
Enrollment: 40 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2011 – 2014
U.S. locations: 1
States / cities: New York, New York

Conditions: Anal Dysplasia, Carcinoma in Situ
Interventions: Gliolan, Vitamin D3 cholecalciferol), Photodynamic Therpay; Drug · Other
Lead sponsor: Abramson Cancer Center at Penn Medicine; Other
Eligibility: 18 Years and older
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2019 – 2022
U.S. locations: 1
States / cities: Philadelphia, Pennsylvania

Conditions: Chronic Kidney Disease, Secondary Hyperparathyroidism, Chronic Renal Insufficiency, Chronic Renal Failure
Interventions: CTAP101 Capsules, CTAP101 Injection; Drug
Lead sponsor: OPKO IP Holdings II, Inc.; Industry
Eligibility: 18 Years to 80 Years
Enrollment: 28 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2009
U.S. locations: 12
States / cities: Peoria, Arizona • Evergreen Park, Illinois • Springfield, Massachusetts + 9 more

Conditions: Relapsing Remitting Multiple Sclerosis
Interventions: Vitamin D3; Drug
Lead sponsor: Johns Hopkins University; Other
Eligibility: 18 Years to 50 Years
Enrollment: 172 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2012 – 2021
U.S. locations: 16
States / cities: Carmichael, California • San Francisco, California • Stanford, California + 12 more

Conditions: Fracture
Interventions: Vitamin D3, Placebo; Drug · Other
Lead sponsor: University of Maryland, Baltimore; Other
Eligibility: 18 Years to 50 Years
Enrollment: 102 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2016 – 2021
U.S. locations: 1
States / cities: Baltimore, Maryland

Conditions: Immunosenescence, Shingles
Interventions: Varicella Zoster Virus Vaccine (Zostavax); Biological
Lead sponsor: University of Colorado, Denver; Other
Eligibility: 60 Years and older
Enrollment: 33 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2010 – 2014
U.S. locations: 1
States / cities: Aurora, Colorado

Conditions: Hypocalcemia, Rickets
Interventions: 1,25-Dihydroxycholecalciferol; Drug
Lead sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); NIH
Eligibility: Not listed
Enrollment: 6 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 1976 – 2009
U.S. locations: 1
States / cities: Bethesda, Maryland

Conditions: Post-Acute COVID-19 Syndrome, Fatigue
Interventions: Dietary intervention to mitigate Post-Acute COVID-19 Syndrome, Attention Control; Other
Lead sponsor: University of Maryland, Baltimore; Other
Eligibility: 50 Years to 94 Years
Enrollment: 56 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2025 – 2028
U.S. locations: 1
States / cities: Baltimore, Maryland

Conditions: Vitamin D Deficiency, Nutritional Deficiency
Interventions: High dose Cholecalciferol, Cholecalciferol; Drug
Lead sponsor: Medical University of South Carolina; Other
Eligibility: 0 Days to 45 Years
Enrollment: 8 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2021 – 2022
U.S. locations: 1
States / cities: Charleston, South Carolina

Conditions: Cirrhosis, Hepatocellular Carcinoma
Interventions: Vitamin D; Drug
Lead sponsor: Johns Hopkins University; Other
Eligibility: 18 Years to 75 Years
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2013 – 2016
U.S. locations: 1
States / cities: Washington D.C., District of Columbia

Conditions: Breast Cancer
Interventions: High Dose Vitamin D, Placebo, Standard Dose Vitamin D3, Letrozole 2.5mg; Dietary Supplement · Drug
Lead sponsor: Qamar Khan; Other
Eligibility: 18 Years and older · Female only
Enrollment: 160 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2009 – 2011
U.S. locations: 2
States / cities: Westwood, Kansas • Wichita, Kansas

Conditions: Opioid Use Disorder
Interventions: [11C]-PHNO, Calcitriol, Placebo Control, PET Scan; Drug · Dietary Supplement · Other + 1 more
Lead sponsor: Yale University; Other
Eligibility: 18 Years to 50 Years
Enrollment: 5 participants
Healthy volunteers: Accepts healthy volunteers
Timeline: 2024 – 2025
U.S. locations: 1
States / cities: New Haven, Connecticut

Conditions: Diabetic Kidney Disease
Interventions: Vitamin D3; Dietary Supplement
Lead sponsor: Medical University of South Carolina; Other
Eligibility: 18 Years and older
Enrollment: 54 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2010 – 2013
U.S. locations: 1
States / cities: Charleston, South Carolina

Conditions: Sickle Cell Disease
Interventions: Vitamin D, Placebo; Drug · Other
Lead sponsor: Wake Forest University Health Sciences; Other
Eligibility: 7 Years to 21 Years
Enrollment: 46 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2009 – 2013
U.S. locations: 1
States / cities: Atlanta, Georgia

Conditions: Osteoporosis, Prostate Cancer
Interventions: Calcium, Zoledronic acid, radiation therapy, LHRH, Vitamin D; Dietary Supplement · Radiation · Drug
Lead sponsor: Radiation Therapy Oncology Group; Network
Eligibility: 18 Years and older · Male only
Enrollment: 109 participants
Healthy volunteers: Healthy volunteers not accepted
Timeline: 2006 – 2014
U.S. locations: 80
States / cities: Chico, California • Los Angeles, California • Pomona, California + 66 more

Search by objective public record fields.

High Dose Vit D Musculoskeletal Symptoms & Bone Density in Anastrozole-Treated Breast Cancer With Marginal Vit D Status

A Study of High-Dose Vit D Versus Standard of Care Vit D Supplementation

S0812 High Dose Cholecalciferol in Premenopausal Women at High-Risk for Breast Cancer

Cholecalciferol and Genistein Before Surgery in Treating Patients With Early Stage Prostate Cancer

High-Dose Cholecalciferol in Treating Patients Receiving Combination Chemotherapy and Bevacizumab as First-Line Therapy For Metastatic Colorectal Cancer

Effect of Vitamin D3 Supplementation on Insulin Resistance and Cardiovascular Risk Factors in Obese Adolescents

Vitamin D Deficiency and Atopic Dermatitis

Vitamin D Supplementation for Adults With Neurofibromatosis Type 1 (NF1)

Study To Understand Fall Reduction and Vitamin D in You

The Effect of Vitamin D Supplementation on Calcium Excretion in Thalassemia: a Dose Response Study

PDT Plus Vitamin D3 for Anal Dysplasia

Pharmacokinetics and Safety Pilot Study of Single-Dose Oral and Intravenous CTAP101 in Stage 3 and 4 Chronic Kidney Disease Subjects

Vitamin D Supplementation in Multiple Sclerosis

Optimal Vitamin D3 Supplementation Strategies for Acute Fracture Healing

Vitamin D Supplementation And Varicella Zoster Virus Vaccine Responsiveness In Older Long-Term Care Residents

Studies With 1,25-Dihydroxycholecalciferol

Dietary Intervention to Mitigate Post-Acute COVID-19 Syndrome

Mothers' Own Milk Optimization for Preterm Infants Project (MoMO PIP) Pilot Study

Study of High-Dose Oral Vitamin D for the Prevention of Liver Cancer

Vitamin D3 for Aromatase Inhibitor Induced Arthralgias

Vitamin D in OUD: Exploration of Alterations on the Dopamine D2/D3 Receptor System

Impact of Vitamin D on Diabetic Kidney Disease in African Americans

High Dose Vitamin D for Sickle Cell Disease

Zoledronate in Preventing Osteoporosis and Bone Fractures in Patients With Locally Advanced Nonmetastatic Prostate Cancer Undergoing Radiation Therapy and Hormone Therapy