View clinical trials related to Vitamin D Deficiency.
Filter by:The prevalence of vitamin D deficiency increases as kidney function declines. As a result, many hemodialysis patients often have low levels of vitamin D. Recent evidence has shown that vitamin D supplementation may improve many aspects of poor health such as heart disease and inflammatory markers. The objectives of this study are to determine how supplementing dialysis patients with ergocalciferol increases vitamin D levels, how long vitamin D levels can be maintained after a 6 month treatment course, and to examine the effect of ergocalciferol on biomarkers of inflammation and vascular health.
This study will look at the effect of 2 treatment regimens that contain vitamin D in a six-month treatment trial of patients with PHPT who are vitamin D deficient. Patients will be assigned randomly to one of 2 regimens, and will be followed with tests of their blood, urine and bones. This study should provide important information on the effect of vitamin D therapy in patients with PHPT. In addition, data from this study will guide physicians as to how best to treat their patients who have PHPT and vitamin D deficiency.
Vitamin D plays a critical role in maintaining bone health, as well as preventing cardiovascular disease, cancer, and various autoimmune diseases, such as diabetes. Vitamin D deficiency is very common in the United States and worldwide, and is now being increasingly recognized and treated. One group in which vitamin D deficiency may be particularly important is patients who have had kidney stones. These patients frequently have elevated levels of calcium in their urine, which is a common and important risk factor for calcium containing kidney stones. Because vitamin D increases absorption of calcium into the blood by the intestines, physicians may be reluctant to prescribe vitamin D therapy to patients with vitamin D deficiency if they also have kidney stones and high amounts of calcium in the urine. They are concerned about the possible risk of increasing the amount of calcium in the urine (and thereby increasing the risk of calcium stones occurring again). However, studies in patients without kidney stones, as well as studies in patients with high calcium levels in the urine, have demonstrated that giving vitamin D is effective and safe and does not increase calcium in the urine. Therefore, the investigators will study the effects of giving vitamin D on the amount of calcium in the urine in patients with a history of kidney stones and elevated calcium in the urine. The investigators will evaluate the safety of giving vitamin D to this particular group of patients.
In cross-sectional and prospective cohort studies, vitamin D deficiency is associated with increased mortality, cardiovascular events including sudden cardiac death and stroke, diabetes, hypertension and impaired function of the immune and musculoskeletal system. The action of vitamin D on the cardiovascular system regulates cardiac function, endothelial and vascular smooth muscle, and, the renin-angiotensin system. Treatment with sufficiently high doses of vitamin D may represent a promising and inexpensive intervention option. To date, there are few data on the effect of cholecalciferol treatment in patients with chronic heart failure. The primary objective of this study is to investigate whether oral vitamin D supplementation improves chronic heart failure (measured with the surrogate parameter of NT-proBNP levels at month 0 and 6).
Research Title: The effect of vitamin D replacement on airway reactivity, allergy and inflammatory mediators in exhaled breath condensate in vitamin D deficient asthmatic children. Introduction: Vitamin D seems to play a role in allergic and asthmatic reactions as an immunomodulator. Asthma disease involves inflammatory process in the lower respiratory tract and airway hyperreactivity. Aim: To assess the effect of Vitamin D replacement on airway reactivity, and allergy and inflammatory mediators in exhaled breath condensate in vitamin D deficient asthmatic children. Design: Double blind placebo control prospective study comparing the effect of Vitamin D replacement and placebo on airway reactivity, allergy and inflammatory mediators in exhaled breath condensate in asthmatic pediatric population with vitamin D deficiency. Participant selection: The study group will consist of pediatric patients (age 6-18 years) followed and treated at the Pediatric Pulmonary Unit at the investigators hospital. Patients with mild-moderate asthma with low or insufficient vitamin D levels that are currently not receiving anti-inflammatory treatment will be recruited. Sample size: 60 participants in the two groups (30 receiving Vitamin D and 30 receiving placebo). Intervention: Vitamin D (14000 units) or placebo will be provided in a similar appearance preparation once weekly for 6 weeks between visit two and three. Three visits will be conducted. Each subject will undergo evaluation including a respiratory questionnaire (visit 1), methacholine challenge test with determination of PC20 (visit 1 or 2 and visit 3), exhaled nitric oxide (eNO) (visit 2, 3), and exhaled breath condensate (EBC) (visit 2,3). Venous blood will be analyzed for complete blood count + eosinophils (visit 1, 3), IGE levels (visit 1, 3), and Vitamin D levels (visit 1, 3). Prick skin test for inhaled allergens will be performed (visit 2, 3). Primary end point: Airway reactivity as assessed by methacholine challenge test. Secondary outcome parameters: All other parameters are the secondary end points.
The objective of this study is to assess the prevalence of vitamin D deficiency in patients with chronic Hepatitis C compared to a matched control group of healthy individuals in the Sioux Falls area. It is the hypothesis of this study that vitamin D deficiency is more common in patients with chronic Hepatitis C compared to the healthy control group.
This study seeks to determine if vitamin D3 absorption in healthy adults will be enhanced in the presence of a meal and if the enhancement will be greater when the meal is low as opposed to high in fat content. The enhancement will result from increased vitamin D absorption. The investigators will test this hypothesis by pursuing the following aims in a 3-mo trial in which up to 70 healthy men and women will be randomized to one of the following meal conditions under which they will take a monthly oral dose of 50,000 IU of vitamin D3: no meal (fasting), a low fat meal, or a high fat meal. The Primary Aim is to identify the meal condition (fasting, low-fat, or high-fat meal) under which the 25OHD3 response to supplemental vitamin D3 is greatest and most consistent. The Secondary Aim is to determine whether vitamin D3 absorption is affected by the meal condition and to determine whether the absorption of vitamin D3 predicts the longer-term 25OHD3 response to supplementation.
Healthy subjects with low Vitamin D levels will be randomly assigned to either Vitamin D replacement or placebo for a period of 8 weeks. Insulin sensitivity will be measured before and after the intervention, and the changes will be compared between the two groups. This will help us understand if Vitamin D replacement improves insulin sensitivity. Serum Retinol Binding Protein 4 levels will also be measured to see if changes in insulin sensitivity are mediated by RBP4.
This is a research study to look at vitamin D deficiency (low levels) in men and women with HIV. As part of your regular medical care, you will be screened for vitamin D deficiency. If your levels are low, and you choose to start using vitamin D supplements, the investigators would like to take some blood before and after you start using vitamin D to see how this affects your levels of HIV, T cells, cholesterol, and other blood levels. The investigators will provide you with vitamin D supplements for the first 24 weeks (6 months) of the study. If you and your physician decide that you should continue taking vitamin D supplements after that time, you will be responsible for purchasing your own vitamin D supplements.
The investigators proposed a pilot study preparatory to developing a randomized trial of vitamin D for the prevention of TB infection. The specific aims are presented below: 1. To recruit subjects, obtain consent, distribute vitamin D supplements to the children in the schools, obtain blood samples and transport them to the United States. 2. To test the hypothesis that daily vitamin D supplementation will increase plasma levels of 25(OH)D, and restore TLR-induced antimicrobial activity in monocytes/macrophages tested in vitro.