Clinical trials
Vitamin D clinical trials
Below are recruiting vitamin d clinical trials, each written for real people, not researchers. We’re tracking 125 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- 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 - NCT02705287Recruiting
Study vitamin D changes in women during pregnancy or adult life
This study measures how vitamin D levels change over about 20 days in women. It may help researchers understand vitamin D patterns in pregnancy and different body sizes, which can guide future health recommendations.
Rochester, New YorkAges 20–39 - NCT07349290Enrolling by invitation
Vitamin D fortified foods for families
This trial tests if eating foods with extra vitamin D can improve vitamin D levels in families. It provides study foods and checks your vitamin D through blood samples.
ColeraineAges 4 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 - NCT07268742Recruiting
Vitamin D and steroids in endocrine disorders
This study looks at how vitamin D and steroids work in people with different hormone-related conditions. It may help us understand why some people have trouble with vitamin D and how it affects their health.
LeuvenAges 18 years+ - NCT06775548Enrolling by invitation
Exercise and vitamins for depression relief
This study tests if combining aerobic and resistance exercises with vitamins D and E can reduce stress and inflammation in people with mild to moderate depression. It may help improve mood and overall well-being.
Karachi, SindhAges 25–35 - NCT07142759Enrolling by invitation
Vitamin D tomato soup trial for low vitamin D levels
This study tests whether a specially grown tomato soup (with extra vitamin D) can raise your vitamin D levels over 3 weeks. You'll eat one soup packet each day. It's for people who have low but not severely low vitamin D.
NorwichAges 18 years+ - NCT07743918Recruiting
Vitamin D and outcomes in locally advanced cervical cancer
This study looks at how vitamin D levels affect treatment results in women with locally advanced cervical cancer who are about to start chemoradiation (chemotherapy plus radiation). It aims to see if higher vitamin D is linked to better outcomes.
Kragujevac, ŠumadijaAges 18–80 - 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 - NCT05448365Recruiting
Vitamins and plant compounds for uterine fibroid symptoms
This trial studies whether a combination of vitamin D, epigallocatechin gallate (a plant compound), D-chiro-inositol, and vitamin B6 can improve symptoms from uterine fibroids. It may help by reducing symptoms such as heavy or irregular bleeding and pelvic pain in people who can undergo surgery.
Francavilla Fontana, ApuliaAges 30–40 - 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+ - NCT06138249Recruiting
Vitamin D supplements for low vitamin D levels
This trial tests two forms of vitamin D (cholecalciferol and calcifediol) to see which better raises vitamin D levels in people with a deficiency. It may help you if your vitamin D is low, but you don't have osteoporosis or liver/kidney problems.
BariAges 18–80 - NCT07099586Recruiting
Vitamin and folic acid levels in women of childbearing age
This study will check the levels of vitamin B12, folic acid, and vitamin D in women who could become pregnant. It aims to learn if certain health factors or supplement use affect these important nutrients.
MostarAges 18–49 - NCT07100795Recruiting
Vitamin B12, Folic Acid and D in Women of Childbearing Age
This study checks the levels of vitamin B12, folic acid, and vitamin D in women who could become pregnant. It aims to find out how common low levels are, so you may learn about your own vitamin levels.
MostarAges 18–49 - NCT07288801RecruitingPhase 4
Vitamin D to prevent preeclampsia again in pregnancy
This trial tests whether taking vitamin D can help pregnant women who had preeclampsia before avoid getting it again. It may protect both you and your baby.
Multan, Punjab ProvinceAges 20–45 - 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 - 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+ - NCT06674122Enrolling by invitation
Vitamin D supplements for preterm babies
This trial tests whether giving preterm babies (born at 28-34 weeks) a higher dose of vitamin D by mouth helps them grow and stay healthy. It may be an option if your baby is already feeding well and doesn't have certain other health problems.
Jakarta, Central JakartaAges 6 months–8 months - NCT05795504Enrolling by invitation
Exercise program to improve calcium and vitamin D levels
This trial compares two exercise routines—resistance training versus high-intensity interval training (HIIT)—to see which better improves calcium intake and vitamin D levels in women. You may be able to join if you are 40–45, have low vitamin D, and are not using hormone therapy.
GizaAges 40–45 - 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+ - 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 - 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 - 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
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Common questions
- Are there clinical trials for vitamin d?
- Yes. Clin2 currently lists 125 recruiting vitamin d 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 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 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.