{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=cholecalciferol",
    "query": {
      "intervention": "cholecalciferol"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 957,
    "total_pages": 96,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=cholecalciferol&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-02T16:22:36.284Z",
  "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": "NCT01561040",
      "title": "Oral Nutrition Impact on Tear Film",
      "overall_status": "UNKNOWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Dry Eye Syndrome"
      ],
      "interventions": [
        {
          "name": "Omega 3, Vitamins A, D3 and E",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Eye and Vision Technologies and Research Institute",
      "sponsor_class": "NETWORK",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "79 Years",
        "sex": "ALL",
        "summary": "18 Years to 79 Years"
      },
      "enrollment_count": 80,
      "start_date": "2012-03",
      "completion_date": "2012-12",
      "has_results": false,
      "last_update_posted_date": "2012-03-26",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 4,
      "location_summary": "Conifer, Colorado • Oak Lawn, Illinois • Lexington, Kentucky + 1 more",
      "locations": [
        {
          "city": "Conifer",
          "state": "Colorado"
        },
        {
          "city": "Oak Lawn",
          "state": "Illinois"
        },
        {
          "city": "Lexington",
          "state": "Kentucky"
        },
        {
          "city": "Creve Coeur",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01561040"
    },
    {
      "nct_id": "NCT01922440",
      "title": "A Registry for Participants With Chronic Hypoparathyroidism",
      "overall_status": "COMPLETED",
      "study_type": "OBSERVATIONAL",
      "phases": [],
      "conditions": [
        "Hypoparathyroidism"
      ],
      "interventions": [
        {
          "name": "No intervention",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "OTHER"
      ],
      "sponsor": "Takeda",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "ALL",
        "summary": "Not listed"
      },
      "enrollment_count": 1339,
      "start_date": "2013-07-30",
      "completion_date": "2026-06-30",
      "has_results": false,
      "last_update_posted_date": "2026-07-14",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 54,
      "location_summary": "Birmingham, Alabama • Tucson, Arizona • Los Angeles, California + 42 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Tucson",
          "state": "Arizona"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "San Jose",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01922440"
    },
    {
      "nct_id": "NCT05387876",
      "title": "Vitamin D Intervention and Associated Changes in the Gut Microbiome and Vitamin D Levels in Healthy Adults",
      "overall_status": "UNKNOWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Colorectal Cancer"
      ],
      "interventions": [
        {
          "name": "Vitamin D intervention",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Placebo intervention",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Baylor University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "79 Years",
        "sex": "ALL",
        "summary": "18 Years to 79 Years"
      },
      "enrollment_count": 43,
      "start_date": "2022-02-14",
      "completion_date": "2023-02-28",
      "has_results": false,
      "last_update_posted_date": "2022-05-24",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Waco, Texas",
      "locations": [
        {
          "city": "Waco",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05387876"
    },
    {
      "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": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Buffalo, New York",
      "locations": [
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01561989"
    },
    {
      "nct_id": "NCT02239874",
      "title": "VITamin D and OmegA-3 TriaL: Effects on Mammographic Density and Breast Tissue",
      "overall_status": "UNKNOWN",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Benign Breast Disease"
      ],
      "interventions": [
        {
          "name": "Vitamin D and fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Fish oil and vitamin D placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D placebo and fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D and fish oil",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "55 Years",
        "maximum_age": "67 Years",
        "sex": "FEMALE",
        "summary": "55 Years to 67 Years · Female only"
      },
      "enrollment_count": 3894,
      "start_date": "2012-07",
      "completion_date": "2023-10",
      "has_results": false,
      "last_update_posted_date": "2022-04-07",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02239874"
    },
    {
      "nct_id": "NCT00538720",
      "title": "Effects of Vitamin D Replacement in Patients With Primary Hyperparathyroidism (PHPT)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Hyperparathyroidism"
      ],
      "interventions": [
        {
          "name": "Vitamin D",
          "type": "DRUG"
        },
        {
          "name": "Four-dimensional computed tomography (4DCT)",
          "type": "DEVICE"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DEVICE"
      ],
      "sponsor": "M.D. Anderson Cancer Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "21 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "21 Years and older"
      },
      "enrollment_count": 22,
      "start_date": "2007-10",
      "completion_date": "2018-05-30",
      "has_results": false,
      "last_update_posted_date": "2019-03-25",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Houston, Texas",
      "locations": [
        {
          "city": "Houston",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00538720"
    },
    {
      "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": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Charleston, South Carolina",
      "locations": [
        {
          "city": "Charleston",
          "state": "South Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00013962"
    },
    {
      "nct_id": "NCT01655810",
      "title": "Vitamin D, Cardiovascular Disease, and African Americans",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Vitamin D Deficiency",
        "Type 2 Diabetes Mellitus",
        "Cardiovascular Disease"
      ],
      "interventions": [
        {
          "name": "Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Calcium carbonate",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Washington University School of Medicine",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": "70 Years",
        "sex": "ALL",
        "summary": "50 Years to 70 Years"
      },
      "enrollment_count": 86,
      "start_date": "2012-08-13",
      "completion_date": "2018-02-09",
      "has_results": false,
      "last_update_posted_date": "2020-06-05",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01655810"
    },
    {
      "nct_id": "NCT01185574",
      "title": "Vitamin D for Improving Metabolic Control and Depressive Symptoms",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Depressive Symptoms",
        "Diabetes"
      ],
      "interventions": [
        {
          "name": "Vitamin D supplementation",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Loyola University",
      "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": 50,
      "start_date": "2009-10",
      "completion_date": "2012-05",
      "has_results": false,
      "last_update_posted_date": "2013-07-11",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Maywood, Illinois",
      "locations": [
        {
          "city": "Maywood",
          "state": "Illinois"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01185574"
    },
    {
      "nct_id": "NCT01635062",
      "title": "The VALIDATE-D Study",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Type 2 Diabetes",
        "Obesity"
      ],
      "interventions": [
        {
          "name": "Calcitriol",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "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": 41,
      "start_date": "2012-09",
      "completion_date": "2015-12",
      "has_results": true,
      "last_update_posted_date": "2017-04-11",
      "last_synced_at": "2026-09-02T16:22:36.284Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01635062"
    }
  ]
}