Vitamin D deficiency

This study looks at whether vitamin D supplements can help people with sarcoidosis who have low vitamin D levels. Researchers will give some participants vitamin D2 and others a placebo, then measure changes in lung function and quality of life. The goal is to see if correcting v…

This study looks at whether taking vitamin D supplements during standard chemotherapy can help more tumors disappear in people with triple-negative breast cancer who are low in vitamin D. About 50 participants will receive vitamin D plus chemotherapy, and researchers will compare…

This trial tests whether giving a single high dose of vitamin A before an allogeneic stem cell transplant can reduce the chance of developing moderate-to-severe chronic graft-versus-host disease (GVHD), a common and serious complication. Adults scheduled for a stem cell transplan…

This study tests an extended-release vitamin D capsule (CTAP101) in 40 children aged 8 to 17 with stage 3 or 4 chronic kidney disease, secondary hyperparathyroidism, and low vitamin D. Participants take one capsule daily at bedtime for 8 weeks. The goal is to see how the body pro…

This study tests whether taking vitamin D daily for 6 months can improve menstrual regularity and mood in teenage girls with PCOS who also have low vitamin D levels. Sixty participants will be randomly assigned to receive either vitamin D or a placebo, and neither they nor their …

This study tests whether adding calcitriol to vitamin D2 helps children with cholestatic liver disease correct their vitamin D deficiency faster than vitamin D2 alone. Cholestasis makes it hard for the body to absorb vitamin D. The trial will enroll 54 children and track vitamin …

This trial is testing whether vitamin D supplements can improve bone density, body composition, strength, walking speed, and physical performance in people hospitalized with neurological disorders like stroke, spinal cord injury, or traumatic brain injury. Participants will recei…

This study tests whether taking vitamin D supplements helps dental implants fuse better with the jawbone in people who are deficient in vitamin D. Ten adults aged 20–60 with low vitamin D levels and a missing tooth in the back of the jaw will receive either vitamin D or no supple…

This study looks at whether vitamin D levels and supplements can reduce inflammation in people with gum disease (periodontitis or gingivitis). Researchers will measure markers of inflammation in blood and gum fluid before and after treatment. The study involves 120 adults with di…

This study tests whether daily high-calorie nutritional supplements can improve growth and development in 200 malnourished children aged 1 to 3 years. One group gets the supplements plus nutrition education, while the other gets only education and diet advice. Researchers will me…

This study tests whether a daily supplement containing vitamin D, EGCG (from green tea), D-chiro-inositol, and vitamin B6 can shrink uterine fibroids in women who are eligible for surgery. Sixty women will take either the supplement or a placebo for three months. The main goal is…

This study looks at whether adding regular exercise (treadmill walking) to vitamin D supplements can improve erectile function in men with type 2 diabetes who also have low vitamin D. Forty men will take vitamin D every two weeks for 12 weeks; half will also walk three times a we…

This study compares two different vitamin D3 supplements to see which one raises vitamin D levels faster and more effectively in adults who are low in vitamin D. About 20 people will take one of the two supplements daily for eight weeks. The goal is to find the best way to correc…

This study looks at three different ways to take vitamin D in people with low levels. Participants will be randomly assigned to one of three groups: a monthly pill, a twice-monthly pill, or daily drops. After one month, researchers will measure vitamin D in the blood and check bo…

This study is testing whether giving high doses of vitamin D3 to critically ill patients with very low vitamin D levels can reduce the chance of death within 28 days. The trial will include 2,400 adults in intensive care units. If successful, this cheap and easy treatment could b…

This study tests whether vitamin D3 supplements can improve heart health in Chinese teenagers who are overweight or obese and have low vitamin D levels. 130 participants will receive either vitamin D3 or a placebo for 12 weeks. Researchers will measure changes in blood pressure, …

This study is testing whether eating almonds can help heal broken thigh and shin bones as effectively as vitamin D supplements, but with fewer side effects and lower cost. The trial will include 136 adults with these fractures, who will receive either almonds, vitamin D, or both,…

This study compares two types of nutrient supplements—small-quantity and medium-quantity—to see if the smaller one works just as well at preventing undernutrition in children aged 6 to 12 months. About 980 infants in Pakistan will receive one of the two supplements daily for 6 mo…

This study compares two different doses of vitamin D3 supplements in pregnant women who have low vitamin D levels. The goal is to see if a higher dose (50,000 IU every two weeks) is better than a lower dose (5,000 IU weekly) at preventing preeclampsia, a serious pregnancy complic…

This study tests whether taking vitamin D supplements can prevent preeclampsia from returning in pregnant women who had it before. About 146 women will be randomly assigned to take either vitamin D or a placebo pill until 36 weeks of pregnancy. Researchers will track blood pressu…

This pilot study tests whether it's possible to run a larger trial comparing plant-based and animal-based oral nutritional supplements (ONS) in hospital patients at risk of malnutrition. Sixty patients from two Dutch hospitals will be randomly assigned to receive either a soy-bas…

This study looks at whether vitamin D levels in the blood and cervical fluid before treatment can predict how well chemoradiotherapy works for locally advanced cervical cancer. Researchers will measure vitamin D in 100 women undergoing standard treatment and track their response …

This study looks at whether a woman's vitamin D level on the day of a frozen embryo transfer affects her chances of getting pregnant and having a baby. Researchers in the UAE will follow 126 women aged 18–40 undergoing frozen embryo transfer. The goal is to see if higher vitamin …

This study is looking at whether people with a common inner-ear condition called benign paroxysmal positional vertigo (BPPV) have lower vitamin D levels than those without it. Researchers will compare vitamin D in 160 adults — half with BPPV and half without. The goal is to see i…

This study gives 200 athletes either high-dose vitamin D3 (4,000 IU daily) or a placebo for 4 to 8 weeks. Researchers measure changes in vitamin D levels, hormones, muscle function, cognitive performance, and body composition. The goal is to see if extra vitamin D improves athlet…

This study looks at how low vitamin D levels affect balance and the way muscles respond to movement. Researchers will compare adults with vitamin D deficiency to healthy adults using simple standing tests and muscle sensors. No treatments or blood draws are involved—just one sess…

This study looks at whether a special type of high-intensity interval training can help overweight adults maintain healthy vitamin D levels during winter. Thirty participants will either exercise three times a week for 12 weeks or just follow a balanced diet. Researchers will mea…

This study will follow 1,000 adults who are taking vitamin D supplements for low vitamin D levels. Researchers will collect health data over 10 years to see how vitamin D use relates to conditions like heart disease, diabetes, cancer, and osteoporosis. The goal is to learn more a…

This study looks at whether the amount of vitamin D in your blood affects your chance of developing thyroid problems while receiving immunotherapy for cancer. Researchers will measure vitamin D and thyroid function before and during standard cancer treatment. The goal is to see i…

This study is checking if pregnant women with low vitamin D are more likely to have a dangerous drop in blood pressure during a C-section when they get spinal anesthesia. Researchers will measure vitamin D levels before surgery and watch blood pressure closely during the procedur…

This study looks at how different forms of vitamin D work in the body. Researchers will measure free vitamin D (the active form) in healthy adults, pregnant women, and people with hormone or kidney problems. The goal is to see if free vitamin D gives a more accurate picture of vi…

This study looks at how taking vitamin D3 and K2 supplements for 90 days changes blood levels and the community of bacteria in the gut (the microbiome) in healthcare workers with low vitamin D. About 96 participants will take either a vitamin D3, K2, both, or a placebo pill. Rese…

This study is looking at 100 children aged 3 to 15 who have had a low-energy fracture (like a fall from standing height). Researchers want to see if vitamin D levels, bone markers, and weight are linked to fracture risk. They will compare children with fractures to those without.…