{
  "api_version": "1",
  "request": {
    "url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=vitamin+D3+800+IU%2Fday",
    "query": {
      "intervention": "vitamin D3 800 IU/day"
    },
    "page_size": 10
  },
  "pagination": {
    "page": 1,
    "page_size": 10,
    "total_count": 45,
    "total_pages": 5,
    "next_page_url": "https://clinicaltrialsfind.com/api/v1/search.json?intervention=vitamin+D3+800+IU%2Fday&page=2&page_size=10",
    "previous_page_url": null
  },
  "source": "remote",
  "last_synced_at": "2026-10-04T07:41:00.735Z",
  "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": "NCT03588884",
      "title": "Repeated-dose Safety, Efficacy, Pharmacokinetic and Pharmacodynamic of CTAP101, Immediate-release Calcifediol, High-dose Cholecalciferol, and Paricalcitol Plus Low-dose Cholecalciferol in Patients With Secondary Hyperparathyroidism, Chronic Kidney Disease 3-4 and Vitamin D Insufficiency",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Secondary Hyperparathyroidism Due to Renal Causes",
        "Vitamin D Insufficiency",
        "CKD Stage 3",
        "CKD Stage 4"
      ],
      "interventions": [
        {
          "name": "Calcifediol Oral Capsule",
          "type": "DRUG"
        },
        {
          "name": "Calcifediol Oral Product",
          "type": "DRUG"
        },
        {
          "name": "Cholecalciferol",
          "type": "DRUG"
        },
        {
          "name": "Paricalcitol Oral Capsule",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG"
      ],
      "sponsor": "OPKO Health, Inc.",
      "sponsor_class": "INDUSTRY",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 69,
      "start_date": "2018-06-08",
      "completion_date": "2020-04-24",
      "has_results": true,
      "last_update_posted_date": "2022-12-09",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 3,
      "location_summary": "Garden Grove, California • Chicago, Illinois • West Bend, Wisconsin",
      "locations": [
        {
          "city": "Garden Grove",
          "state": "California"
        },
        {
          "city": "Chicago",
          "state": "Illinois"
        },
        {
          "city": "West Bend",
          "state": "Wisconsin"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03588884"
    },
    {
      "nct_id": "NCT03629717",
      "title": "RANKL Inhibition and Breast Tissue Biomarkers",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "EARLY_PHASE1"
      ],
      "conditions": [
        "Breast Cancer Prevention",
        "Mammographic Density"
      ],
      "interventions": [
        {
          "name": "Ultrasound-guided core needle biopsy",
          "type": "PROCEDURE"
        },
        {
          "name": "Denosumab",
          "type": "DRUG"
        },
        {
          "name": "Blood draw",
          "type": "PROCEDURE"
        },
        {
          "name": "Calcium",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "PROCEDURE",
        "DRUG"
      ],
      "sponsor": "Washington University School of Medicine",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "35 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "35 Years and older · Female only"
      },
      "enrollment_count": 10,
      "start_date": "2018-06-01",
      "completion_date": "2018-12-03",
      "has_results": false,
      "last_update_posted_date": "2024-10-16",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "St Louis, Missouri",
      "locations": [
        {
          "city": "St Louis",
          "state": "Missouri"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03629717"
    },
    {
      "nct_id": "NCT01469650",
      "title": "Serum 25-hydroxy Vitamin D [25(OH)D] Levels, Supplemental Vitamin D, and Parathyroid Hormone Levels in Premature Infants",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Premature Infants"
      ],
      "interventions": [
        {
          "name": "cholecalciferal",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "cholecalciferol",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Nebraska",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "23 Weeks",
        "maximum_age": "32 Weeks",
        "sex": "ALL",
        "summary": "23 Weeks to 32 Weeks"
      },
      "enrollment_count": 32,
      "start_date": "2012-01",
      "completion_date": "2013-07",
      "has_results": false,
      "last_update_posted_date": "2023-09-06",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Omaha, Nebraska",
      "locations": [
        {
          "city": "Omaha",
          "state": "Nebraska"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT01469650"
    },
    {
      "nct_id": "NCT00580047",
      "title": "Effects of Zoledronic Acid Versus Alendronate on Bone Loss After Kidney and Kidney/Pancreas Transplants",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Renal Insufficiency"
      ],
      "interventions": [
        {
          "name": "Zoledronic Acid",
          "type": "DRUG"
        },
        {
          "name": "Calcium with vitamin D",
          "type": "COMBINATION_PRODUCT"
        },
        {
          "name": "Alendronate",
          "type": "DRUG"
        }
      ],
      "intervention_types": [
        "DRUG",
        "COMBINATION_PRODUCT"
      ],
      "sponsor": "University of Nebraska",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "19 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "19 Years and older"
      },
      "enrollment_count": 59,
      "start_date": "2003-12-01",
      "completion_date": "2014-07-29",
      "has_results": true,
      "last_update_posted_date": "2023-10-04",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Omaha, Nebraska",
      "locations": [
        {
          "city": "Omaha",
          "state": "Nebraska"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00580047"
    },
    {
      "nct_id": "NCT02753283",
      "title": "Preventing Osteoporosis Using Denosumab",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Osteoporosis, Postmenopausal",
        "Osteoporosis",
        "Osteoporotic Fractures"
      ],
      "interventions": [
        {
          "name": "denosumab",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Calcium and Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Susan L. Greenspan",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "65 Years and older"
      },
      "enrollment_count": 201,
      "start_date": "2016-06",
      "completion_date": "2023-08",
      "has_results": true,
      "last_update_posted_date": "2024-09-19",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Pittsburgh, Pennsylvania",
      "locations": [
        {
          "city": "Pittsburgh",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT02753283"
    },
    {
      "nct_id": "NCT00558012",
      "title": "Zoledronic Acid for Osteoporosis in the Elderly",
      "overall_status": "COMPLETED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "NA"
      ],
      "conditions": [
        "Osteoporosis",
        "Bone Loss",
        "Fragility Fractures"
      ],
      "interventions": [
        {
          "name": "Intravenous zoledronic acid",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D 800 IU/daily",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Calcium 1200 mg/daily",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "University of Pittsburgh",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "65 Years and older · Female only"
      },
      "enrollment_count": 181,
      "start_date": "2007-12",
      "completion_date": "2014-02",
      "has_results": true,
      "last_update_posted_date": "2015-07-31",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Pittsburgh, Pennsylvania",
      "locations": [
        {
          "city": "Pittsburgh",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT00558012"
    },
    {
      "nct_id": "NCT04372017",
      "title": "Hydroxychloroquine as Post-Exposure Prophylaxis Against COVID-19 Infection",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE3"
      ],
      "conditions": [
        "COVID-19",
        "SARS-CoV 2"
      ],
      "interventions": [
        {
          "name": "Hydroxychloroquine",
          "type": "DRUG"
        },
        {
          "name": "Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Sanford Health",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "18 Years",
        "maximum_age": null,
        "sex": "ALL",
        "summary": "18 Years and older"
      },
      "enrollment_count": 1,
      "start_date": "2020-05-14",
      "completion_date": "2021-06-04",
      "has_results": true,
      "last_update_posted_date": "2021-12-10",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Sioux Falls, South Dakota",
      "locations": [
        {
          "city": "Sioux Falls",
          "state": "South Dakota"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT04372017"
    },
    {
      "nct_id": "NCT07760948",
      "title": "HMB Plus Vitamin D to Preserve Muscle in Older Adults Starting Semaglutide",
      "overall_status": "NOT_YET_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Type 2 Diabetes Mellitus (T2DM)",
        "Sarcopenia",
        "Obesity",
        "Muscle Loss",
        "Older Adults"
      ],
      "interventions": [
        {
          "name": "Calcium-HMB Plus Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Matching placebo",
          "type": "OTHER"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT",
        "OTHER"
      ],
      "sponsor": "Vanderbilt University Medical Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": "85 Years",
        "sex": "ALL",
        "summary": "65 Years to 85 Years"
      },
      "enrollment_count": 90,
      "start_date": "2026-12-01",
      "completion_date": "2030-11",
      "has_results": false,
      "last_update_posted_date": "2026-08-28",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Nashville, Tennessee",
      "locations": [
        {
          "city": "Nashville",
          "state": "Tennessee"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT07760948"
    },
    {
      "nct_id": "NCT03611049",
      "title": "Improving Functionality in Older People",
      "overall_status": "TERMINATED",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE2"
      ],
      "conditions": [
        "Vitamin D Deficiency"
      ],
      "interventions": [
        {
          "name": "High dose Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        },
        {
          "name": "Low dose Vitamin D3",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Texas Tech University Health Sciences Center",
      "sponsor_class": "OTHER",
      "healthy_volunteers": true,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": "89 Years",
        "sex": "ALL",
        "summary": "65 Years to 89 Years"
      },
      "enrollment_count": 14,
      "start_date": "2018-08-01",
      "completion_date": "2019-07-19",
      "has_results": false,
      "last_update_posted_date": "2019-07-23",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Lubbock, Texas",
      "locations": [
        {
          "city": "Lubbock",
          "state": "Texas"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT03611049"
    },
    {
      "nct_id": "NCT05058976",
      "title": "Romosozumab Use to Build Skeletal Integrity",
      "overall_status": "ACTIVE_NOT_RECRUITING",
      "study_type": "INTERVENTIONAL",
      "phases": [
        "PHASE4"
      ],
      "conditions": [
        "Osteoporosis",
        "Osteoporosis, Postmenopausal",
        "Osteoporosis Fracture"
      ],
      "interventions": [
        {
          "name": "Romosozumab",
          "type": "DRUG"
        },
        {
          "name": "Placebo",
          "type": "DRUG"
        },
        {
          "name": "Zoledronic acid",
          "type": "DRUG"
        },
        {
          "name": "Calcium and Vitamin D",
          "type": "DIETARY_SUPPLEMENT"
        }
      ],
      "intervention_types": [
        "DRUG",
        "DIETARY_SUPPLEMENT"
      ],
      "sponsor": "Susan L. Greenspan",
      "sponsor_class": "OTHER",
      "healthy_volunteers": false,
      "eligibility": {
        "minimum_age": "65 Years",
        "maximum_age": null,
        "sex": "FEMALE",
        "summary": "65 Years and older · Female only"
      },
      "enrollment_count": 184,
      "start_date": "2021-09-15",
      "completion_date": "2027-03-31",
      "has_results": false,
      "last_update_posted_date": "2026-02-17",
      "last_synced_at": "2026-10-04T07:41:00.735Z",
      "location_count": 1,
      "location_summary": "Pittsburgh, Pennsylvania",
      "locations": [
        {
          "city": "Pittsburgh",
          "state": "Pennsylvania"
        }
      ],
      "official_url": "https://clinicaltrials.gov/study/NCT05058976"
    }
  ]
}