View clinical trials related to Vitamin D Deficiency.
Filter by:Vitamin D is a prohormone obtained through diet, supplementation, or sun exposure. Once absorbed, this nutritional vitamin D undergoes a two-step reaction in the liver and in the kidney to become the active hormone, calcitriol. Besides the kidney, many other body tissues are capable of local vitamin D activation. This local tissue activity is important for maintenance of health and relies on adequate levels of nutritional vitamin D. Not only are dialysis patients deficient in calcitriol due to kidney failure, but they are also deficiency in nutritional vitamin D. Low levels of vitamin D have been associated with higher rates of death, heart and blood vessel disease, osteoporosis, falls, cancer, and autoimmune diseases. Despite this, there is a lack of randomized controlled trials (RCT) examining the effects of nutritional vitamin D in hemodialysis (HD) patients. The investigators hypothesize that long-term supplementation with nutritional vitamin D in HD patients improves survival and cardiovascular outcomes. Before embarking on a large scale RCT, the investigators propose a small pilot RCT with 20 hemodialysis patients to: i) To determine the effects of cholecalciferol (vitamin D3) in raising blood vitamin D levels; ii) To determine the feasibility and barriers to successful randomization and adherence to treatment protocols, which will inform subsequent studies.
The purpose of this study is to determine the effect of environmental and genetic influences on Vitamin D status.
Vitamin D deficiency is widely prevalent in India. Serum 25(OH)D levels are <20 ng /ml in up to 90% of them. Recently, in a randomized control trial, investigators have shown that dual cholecalciferol and calcium supplementation lead to significant improvement in hand grip strength and distance covered during six minutes walk test. Present study is being taken to further understand the functional significance of 25(OH)D in terms of its effect on Skeletal muscle strength including surface electromyography (EMG) in a larger cohort involving approximately 200 subjects. The impact of calcium and vitamin D supplementation would be assessed by supplementing them alone and in combination. Besides, the investigators would also assess impact of above supplementation on Th1/Th2 cytokines expression in the peripheral mononuclear cells.
Background: Crohn's disease (CD), a type of Inflammatory Bowel Disease (IBD), is a chronic relapsing inflammatory disorder of the digestive system. CD affects ~112,000 individuals in Canada, of whom 20-25% are diagnosed in childhood or adolescence. The specific cause of CD remains unknown; however, it is hypothesized that CD involves a complex interaction of several factors, including a genetically susceptible host, the intestinal mucosal immune system and microbe population. Several dietary factors have been explored for their potential role in the etiology of CD. However, no consensus on the role of diet has emerged. Recent evidence suggests a plausible link between a lack of Vitamin D and CD. Purpose & Hypothesis: The investigators primary hypothesis is that a greater proportion of pediatric CD patients will achieve optimal 25OHD concentration (> 75 nmol/L) on 2000 IU/d than 400 IU/d Vitamin D. Methods: Pediatric Crohn's Disease patients between 8-18 years of age, and have been in remission for at least 4 weeks as indicated by a Pediatric Crohn's Disease Activity Index (PCDAI) <10 will be recruited for a double-blind, randomized, controlled trial where they will receive one of two dosages of vitamin D (10 or 50 ug/day) and will be asked to continue the supplementation for 6 months. Vitamin D levels will be measured in blood at baseline, 3 months, and 6 months. Dietary vitamin D intake will be estimated using a food frequency and lifestyle questionnaire. Data will be analyzed using multiple regression analysis controlling for baseline values. Expected Results and Conclusions: It is expected that a greater proportion of children receiving the 50 ug/day vitamin D supplement will achieve a blood vitamin level >75 nmol/L compared to children receiving 10 ug/day. This data will aid policy makers, parents/children and healthcare workers in recommending an appropriate vitamin D dosage for the pediatric crohn's population.
Fibroblast growth factor 23 (FGF23) is a newly discovered hormone which regulates phosphate and vitamin D levels. In this study, we are looking at what the normal levels of FGF23 are in adolescent girls and how these levels vary with other hormonal measurements. We will also be looking at whether vitamin D supplementation in adolescents who are deficient in vitamin D alters the levels of FGF23 and other factors including insulin resistance.
Dialysis patients often suffer from defects in their immune system (that part of the body which fights infection). Evidence suggests that Vitamin D deficiency may have a negative effect on immunity, and many dialysis patients are deficient in Vitamin D. We believe that by giving Vitamin D to dialysis patients who are deficient, we may help improve their immune system. This study will test that idea.
Vitamin D deficiency is common world wide. 25 OH vitamin D level is the best indicator of vitamin D status. Vitamin D supplements are available as vitamin D2 or D3, in small daily or large weekly/monthly doses. Controversy continues on the relative potency of vitamin D2 compared to D3 and of daily compared to weekly or monthly doses, in increasing/maintaining total 25 OH vitamin D level. The investigators plan to conduct a controlled trial to compare the effect of various vitamin D supplements on 25 OH vitamin D levels in healthy adults with starting 25 OH vitamin D level between 20 to 50 nmol/L.
Vitamin D insufficiency is a problem of growing concern, given its prevalence in older persons and the association of low vitamin D with multiple major health problems, including mobility and balance deterioration and falls, cardiovascular disease, diabetes, and certain cancers. Sedentary persons are particularly vulnerable for these health problems and generally not adherent to prescribed physical activity. This study will investigate if treatment with vitamin D will benefit physical performance in male veterans age 65 to 95.
Vitamin D deficiency is common in older persons, in particular in residents of nursing homes. This is mainly explained by the fact that older persons do not often go outside in the sunshine. On top of that the capacity of the skin to synthesize provitamin D is decreased and dietary vitamin D intake is low. Vitamin D deficiency leads to osteoporosis, falls and fractures. To prevent morbidity and mortality due to falls and fractures it seems logical to supplement vit D in order to correct the deficiency. The advised daily dose of vit D supplementation is 800 IU. Several studies showed that with this dose the required serum 25(OH)D levels will not be reached. primary objective of this study is: - to investigate whether with a loading dose based on body weight and baseline serum 25(OH)D level more patients reach adequate serum 25(OH)D levels compared to 800 IU a day. - to determine the best consolidation treatment. Secondary objective - is a loading dose based on body weight and baseline serum 25(OH)D level safe to use in residents of nursing homes. - is there a relation between the increase in serum 25(OH)D level and muscle strength (handgrip strength). - is there a relation between the increase in serum 25(OH)D level and mobility (2 minute walk test). Study design: Randomised trial with 3 study groups: - Group 1a. loading dose based on body weight and baseline serum 25(OH)D level + 50.000 IU vit D3/month consolidation therapy. - Group 1b. loading dose based on body weight and baseline serum 25(OH)D level + 25.000 IU vit D3/month consolidation therapy. - Group 2. 800 IU vit D3/ dag. Study population: Vitamine D deficient residents of nursing homes, 65 years or older.
High blood pressure is related to increased risk of cardiovascular disease and death, and accounts for approximately 8 mill deaths worldwide each year. Blood pressure exhibits a seasonal variation with a tendency to increase during winter months. Vitamin D deficiency is more common during months where UVB radiation from the sun is absent, and vitamin D has been associated with high blood pressure. This study will evaluate the effect of vitamin D replacement during winter months on blood pressure and vasoactive hormones in patients with high blood pressure.