{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+-+high+dose&page=3",
    "query": {
      "intervention": "Vitamin D3 - high dose",
      "page": 3
    },
    "page_size": 10
  },
  "pagination": {
    "page": 3,
    "page_size": 10,
    "total_count": 121,
    "total_pages": 13,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+-+high+dose&page=4&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+-+high+dose&page=2&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-11-15T08:35:38.317Z",
  "attribution": "Data derived from public ClinicalTrials.gov records. The official record at https://clinicaltrials.gov/ remains the source of truth for current availability, contacts, and full study details.",
  "notes": [
    "This endpoint exposes only public summary fields — no participant contact emails, phone numbers, or scraped investigator contact details.",
    "For contact information and full protocol detail, follow each trial's `official_url` to the ClinicalTrials.gov record.",
    "This API is a navigational aid. It does not provide medical advice, eligibility determinations, or compensation guarantees."
  ],
  "trials": [
    {
      "nct_id": "NCT04868903",
      "title": "Low vs. Moderate to High Dose Vitamin D for Prevention of COVID-19",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "SARS-CoV-2 Infection"
      ],
      "interventions": [
        {
          "name": "Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Chicago",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 1475,
      "start_date": "2020-11-30",
      "completion_date": "2024-12-01",
      "has_results": true,
      "last_update_posted_date": "2026-07-22",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 2,
      "location_summary": "Chicago, Illinois",
      "locations": [
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04868903"
    },
    {
      "nct_id": "NCT01561989",
      "title": "Cholecalciferol and Flu Vaccine in Treating Healthy Participants",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Healthy, no Evidence of Disease"
      ],
      "interventions": [
        {
          "name": "cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "questionnaire administration",
          "type": "OTHER"
        },
        {
          "name": "trivalent influenza vaccine",
          "type": "BIOLOGICAL"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER",
        "BIOLOGICAL"
      ],
      "sponsor": "Roswell Park Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "64 Years",
        "sex": "ALL",
        "summary": "18 Years to 64 Years"
      },
      "enrollment_count": 11,
      "start_date": "2011-10",
      "completion_date": "2015-06",
      "has_results": true,
      "last_update_posted_date": "2020-03-10",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Buffalo, New York",
      "locations": [
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01561989"
    },
    {
      "nct_id": "NCT04482673",
      "title": "Vitamin D Supplementation in the Prevention and Mitigation of COVID-19 Infection",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "COVID-19",
        "Vitamin D Deficiency",
        "Respiratory Viral Infection"
      ],
      "interventions": [
        {
          "name": "Daily Vitamin D3",
          "type": "DRUG"
        },
        {
          "name": "Daily placebo",
          "type": "DRUG"
        },
        {
          "name": "Bolus vitamin D3",
          "type": "DRUG"
        },
        {
          "name": "Bolus placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Medical University of South Carolina",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 95,
      "start_date": "2020-07-31",
      "completion_date": "2023-12-31",
      "has_results": false,
      "last_update_posted_date": "2023-02-24",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Charleston, South Carolina",
      "locations": [
        {
          "city": "Charleston",
          "state": "South Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04482673"
    },
    {
      "nct_id": "NCT02876822",
      "title": "High Dose Vitamin D Replacement in Patients Undergoing Hematopoietic Stem Cell Transplantation",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Children's Hospital Medical Center, Cincinnati",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "ALL",
        "summary": "Not listed"
      },
      "enrollment_count": 10,
      "start_date": "2016-08-26",
      "completion_date": "2017-05-01",
      "has_results": false,
      "last_update_posted_date": "2020-08-20",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Cincinnati, Ohio",
      "locations": [
        {
          "city": "Cincinnati",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02876822"
    },
    {
      "nct_id": "NCT00263185",
      "title": "High Dose Vit D Musculoskeletal Symptoms & Bone Density in Anastrozole-Treated Breast Cancer With Marginal Vit D Status",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Breast Neoplasms"
      ],
      "interventions": [
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Calcium carbonate",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG",
        "OTHER"
      ],
      "sponsor": "Washington University School of Medicine",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 63,
      "start_date": "2005-11",
      "completion_date": "2009-11",
      "has_results": false,
      "last_update_posted_date": "2014-09-22",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00263185"
    },
    {
      "nct_id": "NCT05016310",
      "title": "A Study of High-Dose Vit D Versus Standard of Care Vit D Supplementation",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Breast",
        "Breast Cancer",
        "Osteoporosis"
      ],
      "interventions": [
        {
          "name": "High Dose Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Standard of Care Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Wake Forest University Health Sciences",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "45 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 45 Years · Female only"
      },
      "enrollment_count": 7,
      "start_date": "2021-09-16",
      "completion_date": "2024-08-15",
      "has_results": false,
      "last_update_posted_date": "2025-07-23",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Charlotte, North Carolina",
      "locations": [
        {
          "city": "Charlotte",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05016310"
    },
    {
      "nct_id": "NCT01097278",
      "title": "S0812 High Dose Cholecalciferol in Premenopausal Women at High-Risk for Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "brca1 Mutation Carrier",
        "brca2 Mutation Carrier",
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER"
      ],
      "sponsor": "SWOG Cancer Research Network",
      "sponsor_class": "NETWORK",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 50 Years · Female only"
      },
      "enrollment_count": 208,
      "start_date": "2011-11-01",
      "completion_date": "2017-09",
      "has_results": false,
      "last_update_posted_date": "2017-11-24",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 360,
      "location_summary": "Anniston, Alabama • Mobile, Alabama • Anchorage, Alaska + 230 more",
      "locations": [
        {
          "city": "Anniston",
          "state": "Alabama"
        },
        {
          "city": "Mobile",
          "state": "Alabama"
        },
        {
          "city": "Anchorage",
          "state": "Alaska"
        },
        {
          "city": "Anchorage",
          "state": "Alaska"
        },
        {
          "city": "Anchorage",
          "state": "Alaska"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01097278"
    },
    {
      "nct_id": "NCT01325311",
      "title": "Cholecalciferol and Genistein Before Surgery in Treating Patients With Early Stage Prostate Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Prostate Adenocarcinoma",
        "Stage I Prostate Cancer",
        "Stage IIA Prostate Cancer",
        "Stage IIB Prostate Cancer"
      ],
      "interventions": [
        {
          "name": "Cholecalciferol",
          "type": "DRUG"
        },
        {
          "name": "Genistein",
          "type": "DRUG"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Pharmacological Study",
          "type": "OTHER"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "National Cancer Institute (NCI)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "MALE",
        "summary": "18 Years and older · Male only"
      },
      "enrollment_count": 15,
      "start_date": "2011-12",
      "completion_date": "2014-07",
      "has_results": true,
      "last_update_posted_date": "2016-08-03",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 11,
      "location_summary": "Birmingham, Alabama • Baltimore, Maryland • Burlington, Massachusetts + 6 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Baltimore",
          "state": "Maryland"
        },
        {
          "city": "Baltimore",
          "state": "Maryland"
        },
        {
          "city": "Burlington",
          "state": "Massachusetts"
        },
        {
          "city": "Minneapolis",
          "state": "Minnesota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01325311"
    },
    {
      "nct_id": "NCT01198548",
      "title": "High-Dose Cholecalciferol in Treating Patients Receiving Combination Chemotherapy and Bevacizumab as First-Line Therapy For Metastatic Colorectal Cancer",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Stage IV Colon Cancer",
        "Stage IV Rectal Cancer"
      ],
      "interventions": [
        {
          "name": "leucovorin calcium",
          "type": "DRUG"
        },
        {
          "name": "bevacizumab",
          "type": "BIOLOGICAL"
        },
        {
          "name": "cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "fluorouracil",
          "type": "DRUG"
        },
        {
          "name": "oxaliplatin",
          "type": "DRUG"
        },
        {
          "name": "pharmacological study",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "BIOLOGICAL",
        "DIETARY_SUPPLEMENT",
        "OTHER"
      ],
      "sponsor": "Roswell Park Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "79 Years",
        "sex": "ALL",
        "summary": "18 Years to 79 Years"
      },
      "enrollment_count": 10,
      "start_date": "2010-08",
      "completion_date": "2012-06",
      "has_results": true,
      "last_update_posted_date": "2014-07-21",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Buffalo, New York",
      "locations": [
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01198548"
    },
    {
      "nct_id": "NCT00858247",
      "title": "Effect of Vitamin D3 Supplementation on Insulin Resistance and Cardiovascular Risk Factors in Obese Adolescents",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Obesity"
      ],
      "interventions": [
        {
          "name": "Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Mayo Clinic",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "12 Years",
        "maximum_age": "18 Years",
        "sex": "ALL",
        "summary": "12 Years to 18 Years"
      },
      "enrollment_count": 51,
      "start_date": "2009-04",
      "completion_date": "2012-12",
      "has_results": true,
      "last_update_posted_date": "2014-05-20",
      "last_synced_at": "2026-11-15T08:35:38.317Z",
      "location_count": 1,
      "location_summary": "Rochester, Minnesota",
      "locations": [
        {
          "city": "Rochester",
          "state": "Minnesota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00858247"
    }
  ]
}