{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+%28Cholecalciferol%29&page=4",
    "query": {
      "intervention": "Vitamin D3 (Cholecalciferol)",
      "page": 4
    },
    "page_size": 10
  },
  "pagination": {
    "page": 4,
    "page_size": 10,
    "total_count": 959,
    "total_pages": 96,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+%28Cholecalciferol%29&page=5&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D3+%28Cholecalciferol%29&page=3&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-09T18:13:46.763Z",
  "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": "NCT00235586",
      "title": "Vitamin D Deficiency: Bone Loss and Vascular Dysfunction",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Postmenopausal Women"
      ],
      "interventions": [
        {
          "name": "10 vit. D deficient subjects take vit. D for 3 months.",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "PROCEDURE"
      ],
      "sponsor": "University of Kansas",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": "90 Years",
        "sex": "FEMALE",
        "summary": "50 Years to 90 Years · Female only"
      },
      "enrollment_count": 40,
      "start_date": "2004-04",
      "completion_date": "2007-09",
      "has_results": false,
      "last_update_posted_date": "2007-09-20",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Kansas City, Kansas",
      "locations": [
        {
          "city": "Kansas City",
          "state": "Kansas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00235586"
    },
    {
      "nct_id": "NCT00013962",
      "title": "Vitamin D Metabolism and the Williams Syndrome",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Williams Syndrome"
      ],
      "interventions": [
        {
          "name": "Vitamin D",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "National Center for Research Resources (NCRR)",
      "sponsor_class": "NIH",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": null,
      "start_date": null,
      "completion_date": null,
      "has_results": false,
      "last_update_posted_date": "2005-06-24",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Charleston, South Carolina",
      "locations": [
        {
          "city": "Charleston",
          "state": "South Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00013962"
    },
    {
      "nct_id": "NCT00182741",
      "title": "Calcitriol, Mitoxantrone, and Prednisone in Treating Patients With Metastatic Prostate Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Prostate Cancer"
      ],
      "interventions": [
        {
          "name": "calcitriol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "mitoxantrone hydrochloride",
          "type": "DRUG"
        },
        {
          "name": "prednisone",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "sponsor": "OHSU Knight Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "100 Years",
        "sex": "MALE",
        "summary": "18 Years to 100 Years · Male only"
      },
      "enrollment_count": 19,
      "start_date": "2004-09",
      "completion_date": "2006-08",
      "has_results": false,
      "last_update_posted_date": "2017-05-03",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Portland, Oregon",
      "locations": [
        {
          "city": "Portland",
          "state": "Oregon"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00182741"
    },
    {
      "nct_id": "NCT00850694",
      "title": "Vitamin D Deficiency in Obese Adolescent Girls and Influence of Vitamin D on Insulin Secretion and Sensitivity",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Vitamin D Deficiency",
        "Obesity",
        "Insulin Resistance"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "University of Alabama at Birmingham",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "10 Years",
        "maximum_age": "18 Years",
        "sex": "FEMALE",
        "summary": "10 Years to 18 Years · Female only"
      },
      "enrollment_count": 114,
      "start_date": "2007-02",
      "completion_date": "2010-10",
      "has_results": false,
      "last_update_posted_date": "2017-04-10",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Birmingham, Alabama",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00850694"
    },
    {
      "nct_id": "NCT00874575",
      "title": "Nutritional Intervention for Age-related Muscular Function and Strength Losses",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Muscle Strength",
        "Sarcopenia"
      ],
      "interventions": [
        {
          "name": "Placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Beta-hydroxy-Beta-methylbutyrate",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Beta-hydroxy-Beta-methylbutyrate and Vitamin D",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "sponsor": "Metabolic Technologies Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "60 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "60 Years and older"
      },
      "enrollment_count": 76,
      "start_date": "2008-11",
      "completion_date": "2013-07",
      "has_results": false,
      "last_update_posted_date": "2014-09-17",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 2,
      "location_summary": "Ames, Iowa • Brookings, South Dakota",
      "locations": [
        {
          "city": "Ames",
          "state": "Iowa"
        },
        {
          "city": "Brookings",
          "state": "South Dakota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00874575"
    },
    {
      "nct_id": "NCT00356512",
      "title": "Physiologic Regulation of FGF-23",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Hypoparathyroidism"
      ],
      "interventions": [],
      "intervention_types": [],
      "sponsor": "National Institute of Dental and Craniofacial Research (NIDCR)",
      "sponsor_class": "NIH",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 20,
      "start_date": "2006-07-19",
      "completion_date": null,
      "has_results": false,
      "last_update_posted_date": "2017-07-02",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Bethesda, Maryland",
      "locations": [
        {
          "city": "Bethesda",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00356512"
    },
    {
      "nct_id": "NCT03471481",
      "title": "Magnesium as a Mediator of Bone and Vitamin D Metabolism in Patients on Antiepileptic Drug Therapy",
      "overall_status": "TERMINATED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Epilepsy",
        "Magnesium Deficiency",
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "No Intervention. Study is Cross Sectional in nature",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Drexel University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "70 Years",
        "sex": "ALL",
        "summary": "18 Years to 70 Years"
      },
      "enrollment_count": 7,
      "start_date": "2015-08-10",
      "completion_date": "2019-08-01",
      "has_results": false,
      "last_update_posted_date": "2021-03-01",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 2,
      "location_summary": "Philadelphia, Pennsylvania",
      "locations": [
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        },
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03471481"
    },
    {
      "nct_id": "NCT00976339",
      "title": "Study of Vitamin D for Premenopausal Women at High Risk for Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Cholecalciferol",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Katherine D. Crew",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "21 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "21 Years and older · Female only"
      },
      "enrollment_count": 20,
      "start_date": "2007-09",
      "completion_date": "2013-12",
      "has_results": true,
      "last_update_posted_date": "2017-09-29",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "New York, New York",
      "locations": [
        {
          "city": "New York",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00976339"
    },
    {
      "nct_id": "NCT01890772",
      "title": "Vitamin D + Telaprevir + Peginterferon + Ribavirin for of Hepatitis C Genotype 1",
      "overall_status": "WITHDRAWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2",
        "PHASE3"
      ],
      "conditions": [
        "Hepatitis C"
      ],
      "interventions": [
        {
          "name": "Telaprevir",
          "type": "DRUG"
        },
        {
          "name": "Peginterferon alfa-2a",
          "type": "DRUG"
        },
        {
          "name": "Ribavirin",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Timothy Morgan, MD",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 0,
      "start_date": "2013-08",
      "completion_date": null,
      "has_results": false,
      "last_update_posted_date": "2014-05-14",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 4,
      "location_summary": "Long Beach, California • Minneapolis, Minnesota • Kansas City, Missouri + 1 more",
      "locations": [
        {
          "city": "Long Beach",
          "state": "California"
        },
        {
          "city": "Minneapolis",
          "state": "Minnesota"
        },
        {
          "city": "Kansas City",
          "state": "Missouri"
        },
        {
          "city": "Philadelphia",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01890772"
    },
    {
      "nct_id": "NCT04965233",
      "title": "Using a Telemedicine Approach in a Genome-wide Association Study of Atopic Dermatitis - Searching for Novel Biomarkers in Clinically Relevant Phenotypes",
      "overall_status": "WITHDRAWN",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Atopic Dermatitis",
        "Eczema",
        "DNA"
      ],
      "interventions": [
        {
          "name": "DNA reports",
          "type": "BEHAVIORAL"
        },
        {
          "name": "Information reports",
          "type": "BEHAVIORAL"
        }
      ],
      "intervention_types": [
        "BEHAVIORAL"
      ],
      "sponsor": "Studies&Me",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 0,
      "start_date": "2020-11-30",
      "completion_date": "2021-12-31",
      "has_results": false,
      "last_update_posted_date": "2021-09-20",
      "last_synced_at": "2026-10-09T18:13:46.763Z",
      "location_count": 1,
      "location_summary": "Redwood City, California",
      "locations": [
        {
          "city": "Redwood City",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04965233"
    }
  ]
}