Active clinical trials for "Vitamin D Deficiency"

The objectives of this study are 1) to assess the prevalence of vitamin D deficiency in a group of sub elite athletes and 2) to identify seasonal changes in vitamin D status and the effect that supplementation may have during the course of a year. The study is a double blinded parallel study design.

Previous studies suggested that vitamin D deficiency is highly prevalent in cirrhotic patients and is related to the degree of liver dysfunction as well as mortality. In gastrointestinal disorders, vitamin D absorption can be highly reduced. We herein aim to investigate the efficacy of oral vitamin D supplementation in cirrhotic patients with vitamin D insufficiency.

Vitamin D plays a key role in keeping normal mineral balance and maintaining bone health. There is accumulating evidence linking deficient vitamin D status with both type 1 and type 2 diabetes. The purpose of this study is to evaluate the effect of high dose vitamin D supplementation (120000 units per month)for 6 months on glucose homeostasis and glycemic control,in vitamin D deficient patients with non-optimally controlled type 2 diabetes mellitus.

It is hypothesised that the efficacy and safety of Vitamin D2 soft capsule to treat the Chronic Kidney Disease Mineral and Bone Disease (CKD-MBD) are equal to 1,25(OH)2 Vitamin D3 (Rocaltrol) in the patients with CKD stage 3-5.

It is well known that postmenopausal women are at risk for osteoporosis. The study hypothesis is that vitamin D deficiency (≤17.5nmol/L) is frequently associated with osteomalacia and will cause low BMD estimation in DXA scan due to insufficient bone mineralization. We assume that among these postmenopausal women, Vitamin D treatment will improve bone mineralization and will cause a rapid increase in BMD. According to the results, bisphosphonates therapy may be an unnecessary treatment. The objective of this study is to evaluate the impact of severe vitamin D deficiency and its correction on Bone Mineral Density (BMD) in postmenopausal women.

Type 2 diabetes (T2D) is an increasingly common and serious condition. Studies show that low vitamin D levels are associated with increased diabetes risk and that vitamin D may protect against diabetes by reducing chronic inflammation and improving insulin sensitivity and insulin secretion. However, no studies have been able to show that vitamin D actually reduces post-prandial blood glucose levels, the most clinically relevant marker of diabetes. Previously the investigators have shown that cheddar cheese and low-fat cheese can be fortified with high levels of vitamin D and that this cheese is at least as a effective as vitamin D supplements in raising blood vitamin D levels. The main purpose of this study is to see whether vitamin D enriched cheese can improve oral glucose tolerance (reduce blood glucose 2 hours after consuming a drink containing 75g sugar) in people who have low vitamin D levels and are at risk for developing T2D. Other aims are to determine the effect of vitamin D may on insulin sensitivity, insulin secretion, markers of inflammation, blood cholesterol levels, and safety markers such as urinary calcium excretion.

Extra-renal sources of 1, 25-dihydroxyvitamin D can be increased to normal serum 1, 25-dihydroxyvitamin D levels in chronic kidney disease patients after administration of high dose 25-hydroxyvitamin D. The investigators observed that 1, 25-dihydroxyvitamin D concentrations were significantly increased after 3 months of omega-3 FA supplementation compared to baseline levels without 25-hydroxyvitamin D administration in dialysis patients. In this study, the investigators hypothesized that omega-3 FA and 25-hydroxyvitamin D supplementations may increase 1, 25-dihydroxyvitamin D concentrations much more compared to 25-hydroxyvitamin D supplementation only in hemodialysis patients with insufficient or deficient 25-hydroxyvitamin D levels.

This is a randomized, double-blind, multicenter, 6-month follow-up trial of low (400 IU/day) versus high (4000 IU/day) dose vitamin D supplementation in individuals with pre- and early stage 1 hypertension and vitamin D deficiency. A total of 530 participants (265 participants per treatment arm) will be randomized between 3 sites. Approximately 2,250 participants will be screened between the 3 sites. Vital signs, 24-hour ambulatory blood pressure monitoring, clinical laboratory safety tests and adverse event assessments will be performed to evaluate the effectiveness of the two doses of vitamin D on blood pressure. Blood samples will be stored for future biomarker assessments. The total duration of the study is anticipated to be 18 months, assuming a 12 month enrollment period.

This is a double-blind placebo controlled pilot study to determine if vitamin D supplementation in hemodialysis (HD) patients will improve physical function and cognition. HD patients have a high prevalence of vitamin D deficiency, cognitive impairment, and physical impairment. Despite standard clinical care with active IV vitamin D during dialysis, HD patients still have markedly low levels of nutritional or dietary vitamin D. IV treatment with vitamin D during dialysis is aimed at treating HD related bone disease. Recent literature shows that oral or nutritional vitamin D has multiple extra-skeletal effects including improvement in cognition and physical function. In this study, the investigators plan to administer oral vitamin D to vitamin D deficient HD patients already receiving standard care with IV vitamin D therapy. Patients will be randomized to receive either placebo or 50,000 IU of vitamin D (cholecalciferol) weekly for 6 months. The investigators' specific aims are to 1) Assess the benefits of correcting nutritional vitamin D deficiency on cognitive and physical function in HD patients receiving routine standard of care, 2) Assess the feasibility of recruiting HD patients for this study, and 3) Evaluate the proposed regimen for safely and effectively increasing nutritional vitamin D levels with oral supplementation. The investigators anticipate that correction of nutritional vitamin D deficiency to optimal levels will improve the high prevalence of cognitive impairment and physical impairment in this population. These results will be used as evidence to support a larger study aimed at treating nutritional vitamin D deficiency in all patients receiving HD. These results may also contribute to a change in current guidelines which place little emphasis on the monitoring and treatment of nutritional vitamin D levels in HD patients. These results are important for the Veteran dialysis population since many of them are required to perform high-level cognitive tasks such as management of complex medical regimens and physical tasks such as orchestrating independent transportation to and from HD sessions and multiple physician appointments.

This is a 12 week pilot and feasibility study with an enrollment goal of 30 subjects. Half of the subjects will be randomized to vitamin D3 and the other half will receive a placebo. Subjects will be referred from the nutrition or renal clinic at Emory. CKD stage 3 and 4 patients will be eligible for participation if they have been determined to have vitamin D deficiency and are not on treatment with vitamin D or vitamin D analogues. Subjects will sign an informed consent form after reviewing the protocol in detail with the principal investigator. A questionnaire would collect information about dietary vitamin D intake, sunlight exposure, and any symptoms of vitamin D deficiency. The subject will have baseline levels of serum vitamin D (25-hydroxyvitamin D), parathyroid hormone (PTH), serum calcium and phosphate, creatinine and other markers of bone turnover. The questionnaires and the blood draws would be repeated on the 6th and 12th week of the study. Subjects will be given 12 pills of each containing either 50,000 IU vitamin D or placebo and asked to take one pill a week. They would be scheduled to return to the clinic after 6 weeks and blood measurements would be repeated. Subjects will be asked to revisit for their final visit at the 12th week when they would have their last blood draw and assessment.