{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D+%28400+IU%2Fday%29",
    "query": {
      "intervention": "Vitamin D (400 IU/day)"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 79,
    "total_pages": 8,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=Vitamin+D+%28400+IU%2Fday%29&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-07T15:50:00.514Z",
  "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": "NCT01417351",
      "title": "Effects of Vitamin D Supplementation During Pregnancy on Clinical Outcomes and Immune Function",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "400 IU vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "2,000 IU Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "USDA, Western Human Nutrition Research Center",
      "sponsor_class": "FED",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "45 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 45 Years · Female only"
      },
      "enrollment_count": 60,
      "start_date": "2010-08",
      "completion_date": "2013-05",
      "has_results": false,
      "last_update_posted_date": "2013-07-23",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 2,
      "location_summary": "Davis, California • Sacramento, California",
      "locations": [
        {
          "city": "Davis",
          "state": "California"
        },
        {
          "city": "Sacramento",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01417351"
    },
    {
      "nct_id": "NCT00567606",
      "title": "Prevention of Osteoporosis in Breast Cancer Survivors",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Postmenopausal Osteoporosis"
      ],
      "interventions": [
        {
          "name": "Strength/Weight Training & Drug/Supplement",
          "type": "OTHER"
        },
        {
          "name": "Drug/Supplement only",
          "type": "COMBINATION_PRODUCT"
        }
      ],
      "intervention_types": [
        "OTHER",
        "COMBINATION_PRODUCT"
      ],
      "sponsor": "University of Nebraska",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "35 Years",
        "maximum_age": "75 Years",
        "sex": "FEMALE",
        "summary": "35 Years to 75 Years · Female only"
      },
      "enrollment_count": 249,
      "start_date": "2002-04-01",
      "completion_date": "2007-12-01",
      "has_results": false,
      "last_update_posted_date": "2023-11-30",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 4,
      "location_summary": "Kearney, Nebraska • Lincoln, Nebraska • Omaha, Nebraska + 1 more",
      "locations": [
        {
          "city": "Kearney",
          "state": "Nebraska"
        },
        {
          "city": "Lincoln",
          "state": "Nebraska"
        },
        {
          "city": "Omaha",
          "state": "Nebraska"
        },
        {
          "city": "Scottsbluff",
          "state": "Nebraska"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00567606"
    },
    {
      "nct_id": "NCT00073073",
      "title": "Exemestane and Celecoxib in Postmenopausal Women at High Risk for Breast Cancer",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Breast Neoplasms"
      ],
      "interventions": [
        {
          "name": "Exemestane",
          "type": "DRUG"
        },
        {
          "name": "Calcium carbonate",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Georgetown University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "Female only"
      },
      "enrollment_count": 46,
      "start_date": "2003-11",
      "completion_date": "2011-12",
      "has_results": true,
      "last_update_posted_date": "2016-05-17",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 2,
      "location_summary": "Washington D.C., District of Columbia • Bethesda, Maryland",
      "locations": [
        {
          "city": "Washington D.C.",
          "state": "District of Columbia"
        },
        {
          "city": "Bethesda",
          "state": "Maryland"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00073073"
    },
    {
      "nct_id": "NCT00048061",
      "title": "MOBILE Study - A Study of Bonviva (Ibandronate) Regimens in Women With Post-Menopausal Osteoporosis",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Post Menopausal Osteoporosis"
      ],
      "interventions": [
        {
          "name": "Ibandronate [Bonviva/Boniva]",
          "type": "DRUG"
        },
        {
          "name": "Calcium",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Hoffmann-La Roche",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "55 Years",
        "maximum_age": "80 Years",
        "sex": "FEMALE",
        "summary": "55 Years to 80 Years · Female only"
      },
      "enrollment_count": 1609,
      "start_date": "2002-04",
      "completion_date": "2004-12",
      "has_results": true,
      "last_update_posted_date": "2018-03-29",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 20,
      "location_summary": "Irvine, California • Loma Linda, California • Los Angeles, California + 17 more",
      "locations": [
        {
          "city": "Irvine",
          "state": "California"
        },
        {
          "city": "Loma Linda",
          "state": "California"
        },
        {
          "city": "Los Angeles",
          "state": "California"
        },
        {
          "city": "Oakland",
          "state": "California"
        },
        {
          "city": "Rancho Mirage",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00048061"
    },
    {
      "nct_id": "NCT01601847",
      "title": "Wheezing in Black Preterm Infants: Impact of Vitamin D Supplementation Strategy",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Wheezing",
        "Allergy"
      ],
      "interventions": [
        {
          "name": "Cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Cholecalciferol",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "DRUG"
      ],
      "sponsor": "Case Western Reserve University",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": null,
        "maximum_age": "1 Year",
        "sex": "ALL",
        "summary": "Up to 1 Year"
      },
      "enrollment_count": 300,
      "start_date": "2013-01",
      "completion_date": "2017-03-12",
      "has_results": true,
      "last_update_posted_date": "2018-06-08",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 5,
      "location_summary": "New York, New York • Cleveland, Ohio • Charleston, South Carolina",
      "locations": [
        {
          "city": "New York",
          "state": "New York"
        },
        {
          "city": "Cleveland",
          "state": "Ohio"
        },
        {
          "city": "Cleveland",
          "state": "Ohio"
        },
        {
          "city": "Cleveland",
          "state": "Ohio"
        },
        {
          "city": "Charleston",
          "state": "South Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01601847"
    },
    {
      "nct_id": "NCT01394484",
      "title": "Dairy Foods Compared to Dietary Supplements and Bone Health",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Osteoporosis",
        "Bone Loss",
        "Osteopenia"
      ],
      "interventions": [
        {
          "name": "Intervention I",
          "type": "OTHER"
        },
        {
          "name": "Intervention II",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "OTHER",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "USDA, Western Human Nutrition Research Center",
      "sponsor_class": "FED",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "50 Years",
        "maximum_age": "65 Years",
        "sex": "FEMALE",
        "summary": "50 Years to 65 Years · Female only"
      },
      "enrollment_count": 12,
      "start_date": "2010-12",
      "completion_date": "2013-02",
      "has_results": false,
      "last_update_posted_date": "2013-02-26",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 1,
      "location_summary": "Davis, California",
      "locations": [
        {
          "city": "Davis",
          "state": "California"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01394484"
    },
    {
      "nct_id": "NCT01769625",
      "title": "Changes in Biomarkers Using Prostaglandin Inhibitors",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Biomarker Change Linked to Breast Cancer"
      ],
      "interventions": [
        {
          "name": "placebo/celecoxib 400 mg and cholecalciferol 400 IU/cholecalciferol 2,000 IU",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Hartford Hospital",
      "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": 31,
      "start_date": "2009-01",
      "completion_date": "2016-11",
      "has_results": false,
      "last_update_posted_date": "2017-08-09",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 1,
      "location_summary": "Grand Forks, North Dakota",
      "locations": [
        {
          "city": "Grand Forks",
          "state": "North Dakota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01769625"
    },
    {
      "nct_id": "NCT01425476",
      "title": "Changes in Breast Cancer Biomarkers Using Synergistic Prostaglandin Inhibitors",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE1",
        "PHASE2"
      ],
      "conditions": [
        "Breast Cancer"
      ],
      "interventions": [
        {
          "name": "Celecoxib",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Cholecalciferol",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Hartford Hospital",
      "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": 45,
      "start_date": "2008-07",
      "completion_date": "2016-11",
      "has_results": false,
      "last_update_posted_date": "2017-08-09",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 1,
      "location_summary": "Grand Forks, North Dakota",
      "locations": [
        {
          "city": "Grand Forks",
          "state": "North Dakota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01425476"
    },
    {
      "nct_id": "NCT04067726",
      "title": "RANKL Inhibition and Mammographic Breast Density",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Dense Breasts"
      ],
      "interventions": [
        {
          "name": "Denosumab",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Calcium",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D3",
          "type": "DRUG"
        },
        {
          "name": "Core needle biopsy",
          "type": "PROCEDURE"
        },
        {
          "name": "Blood draw",
          "type": "PROCEDURE"
        }
      ],
      "intervention_types": [
        "DRUG",
        "PROCEDURE"
      ],
      "sponsor": "Washington University School of Medicine",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "40 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "40 Years and older · Female only"
      },
      "enrollment_count": 210,
      "start_date": "2019-08-27",
      "completion_date": "2026-08-31",
      "has_results": false,
      "last_update_posted_date": "2026-03-31",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04067726"
    },
    {
      "nct_id": "NCT01932788",
      "title": "Preventing Health Disparities During Pregnancy Through Vitamin D Supplementation",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "Vitamin D3 Deficiency"
      ],
      "interventions": [
        {
          "name": "Vitamin D3 4000 IU in gummy form",
          "type": "DRUG"
        },
        {
          "name": "Placebo gummy vitamin",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "Medical University of South Carolina",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": "45 Years",
        "sex": "FEMALE",
        "summary": "18 Years to 45 Years · Female only"
      },
      "enrollment_count": 342,
      "start_date": "2013-01",
      "completion_date": "2018-04-30",
      "has_results": true,
      "last_update_posted_date": "2018-11-21",
      "last_synced_at": "2026-10-07T15:50:00.514Z",
      "location_count": 1,
      "location_summary": "Charleston, South Carolina",
      "locations": [
        {
          "city": "Charleston",
          "state": "South Carolina"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01932788"
    }
  ]
}