Vitamin D Clinical Trials

44 recruitingLast updated: June 17, 2026

There are 44 actively recruiting vitamin d clinical trials across 19 countries. Studies span Not Applicable, Phase 2, Phase 4, Phase 3, Early Phase 1. Top locations include Hangzhou, Zhejiang, China, Taipei, Taiwan, Cairo, Egypt. Updated daily from ClinicalTrials.gov.


Vitamin D Trials at a Glance

44 actively recruiting trials for vitamin d are listed on ClinicalTrialsFinder across 6 cities in 19 countries. The largest study group is Not Applicable with 21 trials, with the heaviest enrollment activity in Hangzhou, Taipei, and Cairo. Lead sponsors running vitamin d studies include Cairo University, First Affiliated Hospital of Zhejiang University, and Jiuda Zhao.

Browse vitamin d trials by phase

Treatments under study

About Vitamin D Clinical Trials

Looking for clinical trials for Vitamin D? There are currently 9 studies actively recruiting participants. Clinical trials offer access to new treatments before they are widely available, and every approved therapy in use today was first tested through a clinical trial.

Below you can browse trials, sign up for alerts when new Vitamin D trials open, and view eligibility criteria for each study. Each listing includes the study phase, locations, and enrollment details.

Frequently Asked Questions

Common questions about Vitamin D clinical trials

A clinical trial is a carefully designed research study that tests new medical treatments, drugs, devices, or approaches in human volunteers. Every approved medication and treatment available today was proven safe and effective through clinical trials.

All clinical trials are reviewed and approved by Institutional Review Boards (IRBs) — independent committees that evaluate patient safety. Trials follow strict protocols, and your health is monitored closely throughout. You can withdraw at any time.

Not necessarily. Many trials compare the new treatment against the current standard of care, meaning all participants receive active treatment. When placebos are used, they are typically combined with standard treatment, not given alone. The trial description will always specify the design.

Under the Affordable Care Act, most private insurers are required to cover routine patient care costs during a clinical trial. The sponsor typically covers the investigational treatment itself. Medicare also covers routine costs for qualifying trials.

Yes. Participation is completely voluntary. You can withdraw at any time, for any reason, without it affecting your access to standard medical care.

Each trial has specific eligibility criteria — including age, diagnosis, disease stage, prior treatments, and general health. Browse the trials listed above and check their eligibility sections. You can also contact the trial site directly to discuss your situation.

Showing 120 of 44 trials

Recruiting
Not Applicable

The Effect of Vitamin D Supplementation on the Anti-inflammatory Response in Periodontal Diseases

GingivitisPeriodontal DiseasesVitamin D Deficiency
Recep Tayyip Erdogan University Training and Research Hospital120 enrolled1 locationNCT07636733
Recruiting
Not Applicable

Effects of High-Dose Vitamin D on Hormones, Neuromuscular Function, Cognition, and Body Composition in Athletes

Vitamin D 25-Hydroxylase DeficiencyVitamin D Deficiency/Insufficiency
The Jerzy Kukuczka Academy of Physical Education in Katowice200 enrolled1 locationNCT07641075
Recruiting

Bone Myoregulation Reflex and Postural Control in Vitamin D Deficiency

Vitamin D Deficiency
Istanbul Physical Medicine Rehabilitation Training and Research Hospital24 enrolled1 locationNCT07435935
Recruiting
Not Applicable

Exercise Training and Vitamin D Metabolism

Vitamin DObesity, Overweight
University of Thessaly30 enrolled1 locationNCT07300332
Recruiting

Vitamin B12, Folic Acid and Vitamin D Status in Women of Reproductive Age

Vitamin D, Vitamin B 12 and Folic Acid ConcentrationsMicronutrient Status in Women of Reproductive AgeVitamin Status Assessment
University of Mostar360 enrolled1 locationNCT07100795
Recruiting
Phase 2

Impact of Vitamin D Supplementation on the Rate of Pathologic Complete Response in Vitamin D Deficient Patients

Triple-Negative Breast CancerInvasive Breast CancerVitamin D Deficiency
Wake Forest University Health Sciences50 enrolled1 locationNCT04677816
Recruiting
Not Applicable

A Household-Based Dietary Intervention Study of Vitamin D Fortified Bread in Irish Families

Vitamin D Deficiency
University College Cork390 enrolled2 locationsNCT07481240
Recruiting
Not Applicable

Evaluation of the Clinical and Psychological Impact of Vitamin D Replacement in Adolescent Females at Risk for Polycystic Ovarian Syndrome (PCOS)

Vitamin D DeficiencyPolycystic Ovarian Syndrome in Adolescent Females
Yale University60 enrolled1 locationNCT04355572
Recruiting
Early Phase 1

Triamcinolone With Vitamin D Synergistic Efficacy in Psoriasis

Plaque PsoriasisVitamin D3
Wright State University24 enrolled1 locationNCT04036188
Recruiting
Not Applicable

Vitamin D, Epigallocatechin Gallate, D-chiro-inositol and Vitamin B6 in Uterine Fibroid

Vitamin DEpigallocatechin GallateUterine Fibroids+3 more
Lo.Li.Pharma s.r.l60 enrolled2 locationsNCT05448365
Recruiting
Not Applicable

Is There a Benefit From Addition of Exercise in Diabetic Patients With ED Who Complain Low Vitamin D?

Diabetes MellitusErectile DysfunctionVitamin D Deficiency
Cairo University40 enrolled1 locationNCT07366970
Recruiting
Not Applicable

Does Vitamin C Increase the Body Heat Generated By The Nervous System?

Vitamin DMetabolism Changes
Colorado State University20 enrolled1 locationNCT07341308
Recruiting

Effect of Vitamin D Deficiency on the Frequency and Severity of Spinal Anesthesia-Induced Hypotension in Pregnant Women Undergoing Cesarean Section

Vitamin D DeficiencyCesarean SectionSpinal Anesthesia Induced Hypotension
Duzce University140 enrolled1 locationNCT07057362
Recruiting
Phase 4

Vitamin D Homeostasis in Sarcoidosis

Vitamin D insufficiencySarcoidosis
University of Texas Southwestern Medical Center90 enrolled1 locationNCT03621553
Recruiting
Not Applicable

Effects of Different Vitamin D3 Formulations in Vitamin D-Deficient Adults

Vitamin D Deficiency
Center for Health Sciences, Serbia20 enrolled1 locationNCT07317830
Recruiting
Not Applicable

Clinical Assessment of Adjunctive Omega-3 Versus Vitamin D Daily Supplements on Active Periodontal Therapy With Stage II Grade B Periodontitis Patients

Vitamin D Deficiency
Cairo University72 enrolled1 locationNCT06654063
Recruiting
Phase 4

Vitamin D for Preventing Recurrent Preeclampsia in Pregnant Women

Vitamin DPregnancyPre-Eclampsia
Nishtar Medical University146 enrolled1 locationNCT07288801
Recruiting

Free Vitamin D and Steroid Metabolism in Endocrine Disorders

Vitamin DVitamin D and Calcium Homeostasis
Universitaire Ziekenhuizen KU Leuven930 enrolled1 locationNCT07268742
Recruiting
Phase 3

The VITDALIZE Study: Effect of High-dose Vitamin D3 on 28-day Mortality in Adult Critically Ill Patients

COVID19Critical IllnessVitamin D Deficiency
Medical University of Graz2,400 enrolled18 locationsNCT03188796
Recruiting
Not Applicable

Prebiotics (Dried Plum) and Immune Function in Postmenopausal Women

T Cell Response to Dried PlumVitamin D Influence on Immune ResponseDried Plum and Immune Function
Indiana University30 enrolled1 locationNCT07222111