{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=vitamin+D+placebo",
    "query": {
      "intervention": "vitamin D placebo"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 436,
    "total_pages": 44,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=vitamin+D+placebo&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-09-27T05:28:22.848Z",
  "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": "NCT01653678",
      "title": "Vitamin D and Omega-3 Hypertension Trial (VITAL Hypertension)",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Hypertension"
      ],
      "interventions": [
        {
          "name": "Vitamin D-3 (cholecalciferol), 2000 IU",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Omega-3 fatty acids (fish oil)",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Fish oil placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "sponsor": "Brigham and Women's Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": "99 Years",
        "sex": "ALL",
        "summary": "50 Years to 99 Years"
      },
      "enrollment_count": 25875,
      "start_date": "2011-11",
      "completion_date": "2026-06",
      "has_results": false,
      "last_update_posted_date": "2025-12-18",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01653678"
    },
    {
      "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": "2026-09-27T05:28:22.848Z",
      "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": "NCT01696435",
      "title": "VITAL-DEP: Depression Endpoint Prevention in the VITamin D and OmegA-3 TriaL",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Depression",
        "Depressive Symptoms",
        "Mood"
      ],
      "interventions": [
        {
          "name": "vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "omega-3 fatty acids (fish oil)",
          "type": "DRUG"
        },
        {
          "name": "Fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D placebo",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "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": 18353,
      "start_date": "2010-07",
      "completion_date": "2025-03-31",
      "has_results": true,
      "last_update_posted_date": "2025-12-10",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01696435"
    },
    {
      "nct_id": "NCT00306774",
      "title": "Vitamin D to Slow Progression of Knee Osteoarthritis",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Osteoarthritis, Knee"
      ],
      "interventions": [
        {
          "name": "Vitamin D (cholecalciferol)",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Placebo",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Tufts Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "45 Years",
        "maximum_age": "90 Years",
        "sex": "ALL",
        "summary": "45 Years to 90 Years"
      },
      "enrollment_count": 146,
      "start_date": "2006-03",
      "completion_date": "2009-06",
      "has_results": false,
      "last_update_posted_date": "2011-09-23",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00306774"
    },
    {
      "nct_id": "NCT01568255",
      "title": "Is Treatment of Vitamin D Deficiency Associated With Resolution of Statin-Induced Muscular Symptoms",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Myopathic Symptoms"
      ],
      "interventions": [
        {
          "name": "Ergocalciferol",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Cedars-Sinai Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 11,
      "start_date": "2012-03",
      "completion_date": "2019-06",
      "has_results": true,
      "last_update_posted_date": "2021-06-10",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Los Angeles, California",
      "locations": [
        {
          "city": "Los Angeles",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01568255"
    },
    {
      "nct_id": "NCT04147624",
      "title": "Reducing the Effects of Aging on Cognition With Therapeutic Intervention of an Oral Nutrient (REACTION): A Pilot Trial",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Cognitive Decline"
      ],
      "interventions": [
        {
          "name": "Souvenaid",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "University of Miami",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "55 Years",
        "maximum_age": "89 Years",
        "sex": "ALL",
        "summary": "55 Years to 89 Years"
      },
      "enrollment_count": 67,
      "start_date": "2021-06-04",
      "completion_date": "2022-12-02",
      "has_results": false,
      "last_update_posted_date": "2023-01-25",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Miami, Florida",
      "locations": [
        {
          "city": "Miami",
          "state": "Florida"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04147624"
    },
    {
      "nct_id": "NCT01141972",
      "title": "The Role of Vitamin D in Menopause: Relationship to Menopausal Symptoms in Body Composition",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1"
      ],
      "conditions": [
        "Hot Flushes",
        "Menopause, Premature",
        "Obesity",
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER"
      ],
      "sponsor": "Kaiser Permanente",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "40 Years",
        "maximum_age": "60 Years",
        "sex": "FEMALE",
        "summary": "40 Years to 60 Years · Female only"
      },
      "enrollment_count": 23,
      "start_date": "2010-09",
      "completion_date": "2012-02",
      "has_results": false,
      "last_update_posted_date": "2013-05-30",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Portland, Oregon",
      "locations": [
        {
          "city": "Portland",
          "state": "Oregon"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01141972"
    },
    {
      "nct_id": "NCT02626299",
      "title": "Assessment of DHA On Reducing Early Preterm Birth",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Preterm Birth"
      ],
      "interventions": [
        {
          "name": "Docosahexaenoic acid - 800mg/day",
          "type": "DRUG"
        },
        {
          "name": "Docosahexaenoic acid - 200mg/day",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DRUG",
        "OTHER"
      ],
      "sponsor": "University of Kansas Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "18 Years and older · Female only"
      },
      "enrollment_count": 1100,
      "start_date": "2016-06-08",
      "completion_date": "2020-10-05",
      "has_results": false,
      "last_update_posted_date": "2021-03-30",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 3,
      "location_summary": "Kansas City, Kansas • Cincinnati, Ohio • Columbus, Ohio",
      "locations": [
        {
          "city": "Kansas City",
          "state": "Kansas"
        },
        {
          "city": "Cincinnati",
          "state": "Ohio"
        },
        {
          "city": "Columbus",
          "state": "Ohio"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02626299"
    },
    {
      "nct_id": "NCT00887354",
      "title": "A Study That Will Compare the Effect of Two Drugs on Participants With Low Bone Mass and a Recent Hip Fracture",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Osteoporosis"
      ],
      "interventions": [
        {
          "name": "Teriparatide",
          "type": "DRUG"
        },
        {
          "name": "Risedronate",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Calcium",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Eli Lilly and Company",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 224,
      "start_date": "2009-04",
      "completion_date": "2015-08",
      "has_results": true,
      "last_update_posted_date": "2019-09-25",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 6,
      "location_summary": "Fort Lauderdale, Florida • New Port Richey, Florida • Orlando, Florida + 3 more",
      "locations": [
        {
          "city": "Fort Lauderdale",
          "state": "Florida"
        },
        {
          "city": "New Port Richey",
          "state": "Florida"
        },
        {
          "city": "Orlando",
          "state": "Florida"
        },
        {
          "city": "New York",
          "state": "New York"
        },
        {
          "city": "Durham",
          "state": "North Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00887354"
    },
    {
      "nct_id": "NCT01630213",
      "title": "Impact of Vitamin D Supplementation on Cardiac Structure and Function",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Cardiovascular Disease"
      ],
      "interventions": [
        {
          "name": "Vitamin D3 + fish oil/fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D3 placebo + fish oil/fish oil placebo",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Massachusetts General Hospital",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "50 Years and older"
      },
      "enrollment_count": 1025,
      "start_date": "2010-07-01",
      "completion_date": "2021-06-30",
      "has_results": false,
      "last_update_posted_date": "2022-04-06",
      "last_synced_at": "2026-09-27T05:28:22.848Z",
      "location_count": 1,
      "location_summary": "Boston, Massachusetts",
      "locations": [
        {
          "city": "Boston",
          "state": "Massachusetts"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01630213"
    }
  ]
}