{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D+placebo&page=13",
    "query": {
      "intervention": "Vitamin D placebo",
      "page": 13
    },
    "page_size": 10
  },
  "pagination": {
    "page": 13,
    "page_size": 10,
    "total_count": 437,
    "total_pages": 44,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D+placebo&page=14&page_size=10",
    "previous_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D+placebo&page=12&page_size=10"
  },
  "source": "remote",
  "last_synced_at": "2026-10-15T01:56:22.903Z",
  "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": "NCT01003275",
      "title": "Metabolic Effects of Paricalcitol",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Chronic Kidney Disease"
      ],
      "interventions": [
        {
          "name": "Paricalcitol",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "University of Washington",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 22,
      "start_date": "2009-10",
      "completion_date": "2011-11",
      "has_results": true,
      "last_update_posted_date": "2014-04-28",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Seattle, Washington",
      "locations": [
        {
          "city": "Seattle",
          "state": "Washington"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01003275"
    },
    {
      "nct_id": "NCT01747447",
      "title": "VITamin D and OmegA-3 TriaL: Effects on Bone Structure and Architecture (VITAL)",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Bone Density",
        "Body Composition",
        "Bone Health"
      ],
      "interventions": [
        {
          "name": "Vitamin D3 placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "omega-3 fatty acids (fish oil)",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 771,
      "start_date": "2012-08",
      "completion_date": "2023-08-02",
      "has_results": true,
      "last_update_posted_date": "2026-04-28",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01747447"
    },
    {
      "nct_id": "NCT01360476",
      "title": "Vitamin D Therapy to Reduce Cardiac Damage Among Vulnerable Hypertensive Patients",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Hypertension",
        "Left Ventricular Hypertrophy"
      ],
      "interventions": [
        {
          "name": "cholecalciferol (Vitamin D)",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Placebo",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Wayne State University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "30 Years",
        "maximum_age": "74 Years",
        "sex": "ALL",
        "summary": "30 Years to 74 Years"
      },
      "enrollment_count": 354,
      "start_date": "2011-08",
      "completion_date": "2015-11",
      "has_results": false,
      "last_update_posted_date": "2015-12-09",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Detroit, Michigan",
      "locations": [
        {
          "city": "Detroit",
          "state": "Michigan"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01360476"
    },
    {
      "nct_id": "NCT00887432",
      "title": "Cholecalciferol Supplement in Treating Patients With Localized Prostate Cancer Undergoing Observation",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Prostate Adenocarcinoma"
      ],
      "interventions": [
        {
          "name": "Cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Laboratory Biomarker Analysis",
          "type": "OTHER"
        },
        {
          "name": "Patient Observation",
          "type": "OTHER"
        },
        {
          "name": "Placebo Administration",
          "type": "DRUG"
        },
        {
          "name": "Quality-of-Life Assessment",
          "type": "OTHER"
        },
        {
          "name": "Questionnaire Administration",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER",
        "DRUG"
      ],
      "sponsor": "Roswell Park Cancer Institute",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "MALE",
        "summary": "18 Years and older · Male only"
      },
      "enrollment_count": 132,
      "start_date": "2009-04-08",
      "completion_date": "2020-06-08",
      "has_results": true,
      "last_update_posted_date": "2021-10-26",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Buffalo, New York",
      "locations": [
        {
          "city": "Buffalo",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00887432"
    },
    {
      "nct_id": "NCT03103750",
      "title": "Vitamin D as a Therapeutic Adjunct in the Stimulant Treatment of ADHD",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "ADHD"
      ],
      "interventions": [
        {
          "name": "Magnetic Resonance Imaging (MRI)",
          "type": "PROCEDURE"
        },
        {
          "name": "PHNO",
          "type": "DRUG"
        },
        {
          "name": "calcitriol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Placebo oral capsule",
          "type": "DRUG"
        },
        {
          "name": "high-resolution research tomography",
          "type": "PROCEDURE"
        },
        {
          "name": "Dextro Amphetamine",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "PROCEDURE",
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Yale University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "50 Years",
        "sex": "ALL",
        "summary": "18 Years to 50 Years"
      },
      "enrollment_count": 24,
      "start_date": "2017-08-15",
      "completion_date": "2023-01-17",
      "has_results": true,
      "last_update_posted_date": "2024-03-19",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "New Haven, Connecticut",
      "locations": [
        {
          "city": "New Haven",
          "state": "Connecticut"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03103750"
    },
    {
      "nct_id": "NCT00996866",
      "title": "Vitamin D Supplementation Requirement in Obese Subjects",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "Vitamin D3",
          "type": "DRUG"
        },
        {
          "name": "placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Winthrop University 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": 27,
      "start_date": "2008-12",
      "completion_date": "2013-08",
      "has_results": true,
      "last_update_posted_date": "2023-07-03",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Mineola, New York",
      "locations": [
        {
          "city": "Mineola",
          "state": "New York"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00996866"
    },
    {
      "nct_id": "NCT02595489",
      "title": "A Pilot Study of Vitamin D in Boys With X-linked Adrenoleukodystrophy",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "X-linked Adrenoleukodystrophy"
      ],
      "interventions": [
        {
          "name": "vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Stanford University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Months",
        "maximum_age": "25 Years",
        "sex": "MALE",
        "summary": "18 Months to 25 Years · Male only"
      },
      "enrollment_count": 21,
      "start_date": "2016-11-21",
      "completion_date": "2020-06-30",
      "has_results": false,
      "last_update_posted_date": "2022-06-09",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Palo Alto, California",
      "locations": [
        {
          "city": "Palo Alto",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02595489"
    },
    {
      "nct_id": "NCT01403051",
      "title": "High Dose Vitamin D and Calcium for Bone Health in Individuals Initiating HAART",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "HIV-1 Infection"
      ],
      "interventions": [
        {
          "name": "EFV/FTC/TDF",
          "type": "DRUG"
        },
        {
          "name": "Calcium Carbonate",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D3",
          "type": "DRUG"
        },
        {
          "name": "Placebo for calcium carbonate",
          "type": "DRUG"
        },
        {
          "name": "Placebo for vitamin D3",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Advancing Clinical Therapeutics Globally for HIV/AIDS and Other Infections",
      "sponsor_class": "NETWORK",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 167,
      "start_date": "2011-09",
      "completion_date": "2013-02",
      "has_results": true,
      "last_update_posted_date": "2018-10-12",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 38,
      "location_summary": "Birmingham, Alabama • Los Angeles, California • Palo Alto, California + 27 more",
      "locations": [
        {
          "city": "Birmingham",
          "state": "Alabama"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Palo Alto",
          "state": "California"
        },
        {
          "city": "San Diego",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01403051"
    },
    {
      "nct_id": "NCT00869622",
      "title": "Antiepileptic Drugs and Osteoporotic Prevention Trial",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Epilepsy",
        "Bone Loss",
        "Osteoporosis",
        "Fractures"
      ],
      "interventions": [
        {
          "name": "Risedronate",
          "type": "DRUG"
        },
        {
          "name": "Placebo + Calcium and Vitamin D",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Boston VA Research Institute, Inc.",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "85 Years",
        "sex": "MALE",
        "summary": "18 Years to 85 Years · Male only"
      },
      "enrollment_count": 80,
      "start_date": "2006-06",
      "completion_date": "2013-01",
      "has_results": true,
      "last_update_posted_date": "2015-07-24",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00869622"
    },
    {
      "nct_id": "NCT01651000",
      "title": "Safety and Efficacy of CTAP101 to Treat Secondary Hyperparathyroidism in Stage 3 or 4 CKD and Vitamin D Insufficiency",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Chronic Kidney Disease",
        "Hyperparathyroidism, Secondary",
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "CTAP101 30 μg capsules",
          "type": "DRUG"
        },
        {
          "name": "Sugar pill to CTAP101 30 μg capsules",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "OPKO IP Holdings II, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 213,
      "start_date": "2012-09",
      "completion_date": "2014-07",
      "has_results": true,
      "last_update_posted_date": "2025-01-13",
      "last_synced_at": "2026-10-15T01:56:22.903Z",
      "location_count": 1,
      "location_summary": "Bannockburn, Illinois",
      "locations": [
        {
          "city": "Bannockburn",
          "state": "Illinois"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01651000"
    }
  ]
}