| Recruiting | Exercise Training and Vitamin D Metabolism NCT07300332 | University of Thessaly | N/A |
| Not Yet Recruiting | Non-inferiority RCT on Fish Waste-Derived vs. Synthetic Vitamin D Supplementation in Healthy Adults With Subop NCT07127796 | University of Bologna | N/A |
| Recruiting | Vitamin D for Preventing Recurrent Preeclampsia in Pregnant Women NCT07288801 | Nishtar Medical University | Phase 4 |
| Recruiting | Does Vitamin C Increase the Body Heat Generated By The Nervous System? NCT07341308 | Colorado State University | N/A |
| Recruiting | Efficacy and Safety of Vitamin D Supplementation in Pediatric Patients with Obesity NCT06847373 | Coordinación de Investigación en Salud, Mexico | N/A |
| Completed | Bone Turnover Markers and Vitamin D Survey Among Health Professionals in Taiwan NCT07387458 | National Cheng-Kung University Hospital | — |
| Recruiting | Effect of Vitamin D Supplementation on Chemotherapy Side Effects After Adjuvant Chemotherapy for Breast Cancer NCT06642441 | Jiuda Zhao | N/A |
| Recruiting | Effect of Vitamin D Supplementation on the Efficacy and Adverse Effects of Neoadjuvant Therapy in Patients wit NCT06642428 | Jiuda Zhao | N/A |
| Completed | Omega-3 Supplementation and Mental Health in College Students NCT07391254 | University of Colorado, Colorado Springs | N/A |
| Recruiting | Assessing Bone Fracture Healing Effect of Almonds NCT07153302 | Aga Khan University Hospital, Pakistan | N/A |
| Recruiting | Free Vitamin D and Steroid Metabolism in Endocrine Disorders NCT07268742 | Universitaire Ziekenhuizen KU Leuven | — |
| Completed | Association of Vitamin D Intake, and Associated Factors with Low Back Pain: a Retrospective Cohort Study NCT06765382 | Mutah University | — |
| Completed | Effect of Vitamin D Supplementation on Testosterone Level in Women With Polycystic Ovary Syndrome NCT06101147 | Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh | Phase 2 |
| Unknown | Relationships Between Vitamin D and Orthopedic Trauma NCT04564625 | Methodist Health System | — |
| Unknown | The Efficacy and Safety of Topical Vitamin D and Supplementation In Acne Vulgaris The Study of VDR, IL-1β, IL- NCT05758259 | Indonesia University | Phase 4 |
| Completed | Vitamin D Supplementation Prior to Non-surgical Periodontal Therapy NCT05398770 | University of Tromso | N/A |
| Completed | Clinical and Radiographic Evaluation of Topical Vitamin D on Immediate Dental Implants NCT06806423 | Suez Canal University | N/A |
| Recruiting | Vitamin D, Epigallocatechin Gallate, D-chiro-inositol and Vitamin B6 in Uterine Fibroid NCT05448365 | Lo.Li.Pharma s.r.l | N/A |
| Completed | The Effects of Vitamin D and Calcium Supplementation to Parathyroid Hormone in CHB Patients Treated With TDF NCT05313477 | Mahidol University | Phase 4 |
| Completed | Pharmacokinetics Evaluation of Vitamin D Formulations NCT05209425 | Factors Group of Nutritional Companies Inc. | N/A |
| Unknown | Vitamin D Supplementation for the Prevention of GDM NCT05208827 | Women's Hospital School Of Medicine Zhejiang University | EARLY_Phase 1 |
| Unknown | The Effect of Vitamin D and Calcium Supplementation on the Prevention of Stress Fractures. NCT05186194 | Xijing Hospital | N/A |
| Unknown | Vitamin D Supplementation and TB NCT01992263 | Cornell University | N/A |
| Completed | Relationship Between Serum Vitamin D and Atherosclerosis in Hemodialysis Patients NCT07200804 | Ain Shams University | — |
| Completed | Assessment of the Safety & Tolerability of Long-term Use of Patented Transdermal Patches in Healthy Adults. NCT04851990 | Horopito Limited | N/A |
| Completed | The Effect of an Acute Bout of Exercise on Serum Vitamin D Concentration NCT05214027 | University of Bath | — |
| Completed | Efficacy of Vitamin D Treatment in Pediatric Patients Hospitalized by COVID-19 NCT04502667 | Coordinación de Investigación en Salud, Mexico | Phase 3 |
| Completed | Efficacy of Vitamin D Supplementation to Prevent the Risk of Acquiring COVID-19 in Healthcare Workers NCT04535791 | Coordinación de Investigación en Salud, Mexico | Phase 3 |
| Unknown | Correlation Between Vitamin D and Symptoms Severity of Autonomic Nervous Mediated Syncope Child and it 's RAAS NCT04844957 | Kongyujie | EARLY_Phase 1 |
| Unknown | Development of a Screening Tool for the Risk of Vitamin D Deficiency NCT04404842 | University of Pavia | — |
| Completed | Vitamin D, Hashimato's Thyroiditis and Thyroid Functions NCT06726967 | Ankara Yildirim Beyazıt University | — |
| Completed | Evaluation of the Efficacy of Vertistop® D and Vertistop® L in the Prevention of BPPV Recurrence NCT05748249 | Fondazione Policlinico Universitario Agostino Gemelli IRCCS | Phase 1 |
| Completed | Vitamin D In the Prevention of Viral-induced Asthma in Preschoolers NCT03365687 | Professor Francine Ducharme | Phase 3 |
| Completed | Preventing Curve Progression and the Need for Bracing in Adolescent Idiopathic Scoliosis With Calcium + Vitami NCT03533010 | Chinese University of Hong Kong | N/A |
| Withdrawn | Effect of Ergocalciferol on Iron Metabolism in Individuals With Chronic Kidney Disease NCT03073369 | University of Alabama at Birmingham | Phase 4 |
| Completed | The Effect of Vitamin D on in Vitro Fertilization Outcome NCT02361827 | The First Affiliated Hospital of Zhengzhou University | — |
| Completed | Diamyd Administered Into Lymph Nodes in Combination With Vitamin D in Type 1 Diabetes NCT03345004 | Diamyd Medical AB | Phase 2 |
| Suspended | Vitamin D Level Among Athletes in Uzbekistan NCT03623763 | Research Institute of Epidemiology, Microbiology and Infectious Diseases, Uzbekistan | — |
| Completed | 6 Years Study on Changes in Bone Quality, Bone Turnover and Curve Severity in AIS With and Without Calcium and NCT02904421 | Chinese University of Hong Kong | — |
| Completed | Effects of Vitamin D and Omega-3 on Cerebrovascular Disease NCT04070833 | Brigham and Women's Hospital | N/A |
| Completed | The Effect of Oral Vitamin D Supplements on Fusion Outcome in Patients Receiving Elective Lumbar Spinal Fusion NCT05023122 | Show Chwan Memorial Hospital | N/A |
| Completed | Vitamin D, Bones, Nutritional and Cardiovascular Status NCT01832623 | Hospices Civils de Lyon | N/A |
| Completed | Effects of Cholecalciferol Supplementation on Bone Health and Muscle Strength in Adults During Post-burn Perio NCT02092701 | University of Liege | N/A |
| Withdrawn | The Influence of Proton Pump Inhibitors (PPI's) on Blood Levels of 25-Hydroxyvitamin D. NCT01302704 | Mike O'Callaghan Military Hospital | — |
| Completed | Vitamin D Intervention in Infants - Pilot NCT01275885 | Helsinki University Central Hospital | Phase 4 |
| Completed | Longitudinal Study of Patients Following Long Bone Fracture NCT01170572 | Barts & The London NHS Trust | — |
| Unknown | Vitamin D Zinc Fever NCT01080950 | Assaf-Harofeh Medical Center | — |
| Completed | Vitamin D Status and Dose Response in Infants NCT01042561 | University of Nebraska | N/A |
| Completed | Antenatal Vitamin D3 Dose-finding and Safety Study NCT00938600 | Johns Hopkins Bloomberg School of Public Health | Phase 1 |
| Completed | Vitamin D and Physical Function in Older Adults NCT00710957 | Wake Forest University Health Sciences | — |
| Completed | Role of Fat Tissue in Vitamin D Metabolism NCT00033826 | Tufts University | — |