Clinical trials
Vitamin D Deficiency clinical trials
Below are recruiting vitamin d deficiency clinical trials, each written for real people, not researchers. We’re tracking 39 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- NCT04677816RecruitingPhase 2
Vitamin D for a better response to chemotherapy
This study tests whether taking high-dose vitamin D before and during chemotherapy helps eliminate more cancer before surgery in people with triple-negative breast cancer who are low in vitamin D.
Winston-Salem, North CarolinaAges 18 years+ - NCT06450925RecruitingPhase 2
Vitamin A supplement for stem cell transplant patients
This study tests whether giving vitamin A by mouth to adults before and after a stem cell transplant can help their recovery. The goal is to see if it reduces complications and improves overall outcomes.
Tampa, FloridaAges 18 years+ - NCT04355572Recruiting
Vitamin D replacement study for teens at risk of PCOS
This study looks at how taking vitamin D affects hormone levels and emotional well-being in teen girls who may develop PCOS. If you have low vitamin D and meet PCOS risk criteria, the study may test whether vitamin D helps you feel and function better.
New Haven, ConnecticutAges 13–21 - NCT04987073Recruiting
Vitamin D type added for CYP24A1 vitamin D deficiency
This study tests a vitamin D-like medicine for people with a specific genetic cause of low active vitamin D (CYP24A1 deficiency). If you have the right gene change, it may help your body use vitamin D more normally.
Caen, NormandyAges 18 years+ - NCT06903247Enrolling by invitation
Ultrasound Brain Findings in Pregnancy with Low Vitamin D
This study uses ultrasound to check for differences in the baby's brain and spine in pregnant women with low vitamin D levels. It aims to see if vitamin D deficiency during pregnancy is linked to certain ultrasound findings.
SanliurfaAges 18–50 - NCT07012161RecruitingEarly Phase 1
Vitamin D for fibroid symptoms in women with low vitamin D
This trial tests whether taking vitamin D3 can help reduce symptoms like heavy bleeding or pressure from uterine fibroids. It is for women who have fibroids and are also low in vitamin D.
Dhaka, SahabagAges 18–50 - NCT06943443Enrolling by invitation
Vitamin D and expander treatment for teens
This trial looks at whether vitamin D levels affect how well a special expander (MARPE) works to fix a narrow upper jaw in teens. If you are 15–18 and have a narrow upper jaw, you may be able to join.
Konya, MeramAges 16–18 - NCT07670611RecruitingPhase 4
Vitamin D2 alone or with calcitriol for children with liver disease
This trial compares two types of vitamin D—one is plain vitamin D2, the other is vitamin D2 plus a more active form (calcitriol)—to see which works better for children with liver problems and low vitamin D levels.
BangkokAges Up to 18 years - NCT03989778RecruitingPhase 2
Vitamin D for PCOS with low vitamin D
This Phase 2 study tests whether vitamin D can improve hormone balance and infertility-related problems in people with PCOS who have low vitamin D. You may be able to join if you’re between 18 and 36, have primary infertility, and meet specific PCOS and vitamin D blood test levels.
Karachi, SindhAges 18–36 - NCT04179370Recruiting
Vitamin D and health in British African-Caribbean women
This study looks at vitamin D levels and how they relate to overall health in British African-Caribbean women. It may help researchers understand whether vitamin D support or lifestyle changes could benefit this group.
GuildfordAges 18 years+ - NCT04331639Recruiting
High-dose vitamin D for kids with IBD on biologic therapy
This trial studies whether giving a higher dose of vitamin D3 helps children and teens with inflammatory bowel disease (Crohn’s or ulcerative colitis) who have low vitamin D levels. Participants are already on biologic medicines and will be treated while monitoring blood (and safety) related to vitamin D.
Boston, MassachusettsAges 5–25 - NCT05449522Recruiting
Vitamin D after major trauma in ICU patients
This trial tests whether giving vitamin D to adults in the ICU after major trauma can improve outcomes. It’s meant for people who don’t have certain conditions that raise calcium levels or make feeding with the study plan unsafe.
TaipeiAges 20 years+ - NCT05860270RecruitingPhase 4
Vitamin D by mouth to prevent peritoneal dialysis peritonitis
This trial tests whether taking vitamin D by mouth can lower the risk of peritonitis (a painful infection of the lining around the abdomen) in people on peritoneal dialysis. You might benefit if your vitamin D level is low and you meet other safety requirements.
Beijing, Beijing MunicipalityAges 19 years+ - NCT05937789Recruiting
Vitamin D3 during early ICU care to help critically ill adults
This trial tests whether starting vitamin D3 soon after ICU admission helps critically ill adults with low vitamin D levels. It may help correct low vitamin D and possibly improve recovery, depending on your health situation.
TaipeiAges 18 years+ - NCT06571344Recruiting
Vitamin D in dialysis patients
This trial checks if measuring vitamin D in dialysis patients can lead to better treatment, then gives vitamin D supplements to those who are low. It may help improve your bone and heart health.
GdanskAges 18 years+ - NCT07684404Recruiting
Vitamin D for dental implant success
This trial tests if taking vitamin D improves how well dental implants bond with the jawbone in people with low vitamin D levels. It may help strengthen the implant integration.
Cairo, New CairoAges 20–60 - NCT07057362Recruiting
Vitamin D and blood pressure during C-section under spinal anesthesia
This trial checks if low vitamin D levels can make a drop in blood pressure more likely or severe during a C-section with spinal anesthesia. It may help find ways to better monitor or prevent blood pressure problems during surgery.
Düzce, MerkezAges 18–40 - NCT07317830Recruiting
Comparing vitamin D3 forms for low vitamin D
This study compares different forms of vitamin D3 to find which works best for adults with low vitamin D levels. If you have a vitamin D deficiency and are generally healthy, this trial may help determine the most effective supplement for you.
BelgradeAges 18–80 - NCT07366970Recruiting
Exercise and vitamin D for erectile dysfunction in diabetes
This trial tests whether adding exercise to your routine helps with erectile dysfunction if you have type 2 diabetes and low vitamin D levels. It aims to see if exercise can improve your symptoms.
Dokki, Giza GovernorateAges 35–45 - NCT07435935Recruiting
Vitamin D deficiency and balance study
This study looks at how vitamin D deficiency affects your body's ability to maintain balance and control posture. It may help explain why low vitamin D can impact muscle and bone health.
IstanbulAges 20–40 - NCT07491965Recruiting
Vitamin D and Benign Paroxysmal Positional Vertigo (BPPV)
This study looks at whether people with BPPV (a type of vertigo triggered by head movement) have lower vitamin D levels than those who don't have vertigo. Your participation may help clarify if vitamin D plays a role in BPPV.
SohagAges Any age - NCT07636733Recruiting
Vitamin D for Gum and Bone Health in Periodontal Disease
This study tests whether vitamin D supplements can reduce inflammation and improve healing in people with gum disease, ranging from mild gingivitis to advanced periodontitis. Researchers will compare how vitamin D affects different stages of gum disease.
RizeAges 18–70 - NCT07641075Recruiting
High-Dose Vitamin D Effects in Experienced Athletes
This study tests whether high-dose vitamin D supplements improve athletic performance, brain function, and body composition in experienced athletes. Researchers will measure hormones, muscle strength, thinking ability, and muscle mass over time.
Katowice, Mikołowska 72aAges 17–60 - NCT07565064Enrolling by invitation
Vitamin D Blood Test Stability Study
This study tests how accurately a vitamin D blood test works with fresh versus frozen samples. Your blood samples will help researchers understand the best way to store and measure vitamin D levels.
Salem, New HampshireAges 22 years+
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Common questions
- Are there clinical trials for vitamin d deficiency?
- Yes. Clin2 currently lists 39 recruiting vitamin d deficiency studies from the U.S. registry, each rewritten for real people, not researchers, so you can see what it’s testing and who it’s for.
- How do I know if I qualify for a vitamin d deficiency trial?
- Each study lists its eligibility criteria — rules about age, diagnosis, and prior treatments. On every Clin2 trial page we explain these in words written for real people and offer a short, optional pre-screen for a fit read. The study team makes the final decision.
- Does it cost anything to join a vitamin d deficiency trial?
- Using Clin2 is always free. Many trials cover the cost of the study treatment and related visits; some reimburse travel. The study team explains exactly what’s covered before you decide.
Related conditions
Clin2 helps you find and understand clinical trials and does not provide medical advice. Study data comes from ClinicalTrials.gov. Talk with your doctor about whether a specific trial is right for you.