View clinical trials related to Vitamin D Deficiency.
Filter by:Cardiovascular disease is the most common cause of mortality and morbidity worldwide. Recently, a growing body of evidence has identified Vitamin D deficiency as a potential risk factor for cardiovascular disease. Therefore, there is an increasing interest to explore the mechanism in which vitamin D deficiency affect the cardiovascular system. The investigators want to examine the relationship between serum vitamin D levels and the coagulation status in the subjects. The applied the calibrated automated thrombogram (CAT) to assess thrombin generation in plasma as a measure of overall thrombotic activity, and thus to suggest a mechanism that may explain the link between vitamin D deficiency and cardiovascular disease. Our study population are going to include 100 patients from the internal departments in Emek hospital, who present with chest pain but without acute coronary syndrome (ACS). The investigators will take blood samples from the subjects to measure the serum vitamin D levels and the generation of thrombin. The patients will be divided into four groups according to the level of vitamin D to evaluate the effect of vitamin D levels in the blood on coagulability and thrombotic activity in these patients.
In this study, we will test the central hypothesis that enhancement of vitamin D status in obese and overweight children will improve their vascular health and their cardiovascular disease (CVD) and metabolic syndrome risk profile.
Vitamin D is an essential nutrient. Deficiency of vitamin D is widespread. The prevalence of vitamin D deficiency in early preterm infants is unknown. The American Academy of Pediatrics recommends a daily intake of 400 IU in order to achieve a serum concentration of 20 ng/ml of vitamin D. This recommendation presumes exposure to sunlight, the best source of vitamin D. This study assesses vitamin D status at birth and during hospital stay in infants delivered delivered at earlier than or at 32 weeks gestation. We also assess the adequacy of intake relative to the target set by the American Academy of Pediatrics for children.
Retinal vein occlusion (RVO) is a common vascular disease of the eye. Studies have shown that the risk of venous thrombosis is higher in winter so even concerning RVO. Studies have shown a possible link between sun exposure and venous thrombosis. Vitamin D levels have been shown to have a similar seasonal variation, with a peak occurring in the summer. The primary source of vitamin D is from sunlight when ultraviolet B (UVB) radiation penetrates the skin and converts 7-dehydrocholesterol to 25-hydroxycholecalciferol vitamin D3 (25-OHVitD) via previtamin D. In Stockholm situated at latitude 59˚ 20΄ North, it is not possible to synthesize vitamin D at sufficient levels in winter and the exposure time required to reach a standard dose is impractical from at least October through March. The aim of the study is to evaluate vitamin D levels in central retinal vein occlusion (CRVO) patients and compare them with the vitamin D levels in randomly selected control patients matched for age and month of disease onset. This is to evaluate whether vitamin D deficiency may be a risk factor in the onset of CRVO. The hypothesis of the study is that patients with CRVO have lower levels of vitamin d than matched controls.
To compare the efficacy of two high dose vitamin D3 regimens (5,000 IU daily vs. 50,000 IU weekly) used clinically for the treatment of vitamin D deficiency versus a low dose of vitamin D3 used for supplementation (1,000 IU daily) in a clinical sample of predominantly Hispanic and black adolescents with vitamin D deficiency [25(OH)D level <20 ng/ml] by assessing change in 25(OH)D levels before and after 8 weeks of treatment. To compare the effects of vitamin D repletion [25(OH)D level >20 ng/mL] on selected musculoskeletal, cardiometabolic and immune markers in predominantly Hispanic and black adolescents with vitamin D deficiency [25(OH)D level < 20 ng/mL]. Hypothesis 1: Increase in vitamin D level will be associated with improvement in musculoskeletal, cardiometabolic, and immune markers including blood pressure, waist circumference, musculoskeletal symptoms, asthma severity and hand-grip strength.
The purpose of this study was to determine whether vitamin D2 and vitamin D3 in orange juice are effective at raising vitamin D levels in the blood and if vitamin D2 and vitamin D3 in orange juice raised blood levels of 25(OH)D as well as vitamin D3 and vitamin D2 supplements.
Vitamin D deficiency has been linked to endothelial dysfunction in adults. Obese adolescents have a high prevalence of Vitamin D deficiency as well as evidence of endothelial dysfunction. Our hypothesis is that supplementation of Vitamin D deficient adolescents with Vitamin D would lead to improvement in endothelial dysfunction.
Vitamin D has a range of biological effects of public health relevance. Vitamin D status is assessed on levels of its metabolite 25-hydroxyvitamin D [25(OH)D], where levels < 50 nmol/L indicate insufficiency. Despite studies indicating that the vitamin D intake among Swedish children are significantly below recommendations, little is known of their vitamin D status. The investigators have recently found inadequate vitamin D status in pre-school children living in northern Sweden, especially in dark-skinned children and during the winter months despite vitamin D intakes meeting the recommendations. Overall, 25% of the light skinned and 40% of the dark skinned children had S-25(OH) D <50 nmol/L (Öhlund I, unpublished data). The aim is to examine which amount of vitamin D is needed to maintain or increase S-25(OH)D to ≥50 nmol/L among 97.5% of the participants regardless of skin color or geographic location (northern or southern Sweden). Furthermore the investigators will examine if vitamin D status affects on health markers as bone density, blood pressure, serum lipids, fatty acids, inflammatory and immunological markers and mental wellbeing. Children aged 5-8 years living either northern (Umeå) or southern Sweden (Malmö) will be recruited to this trial during November-December 2012. They will be randomized to a vitamin D supplement of either 10 or 25 g per day, or in Malmö also placebo to be used for three months. The randomization will be stratified according to skin color (light or dark) according to a method using visual inspection and interviews of parents/guardians. The investigators will use a 2×2×2 factorial design to investigate the effects of two different doses of vitamin D (10 µg and 25 µg) in children with dark and light skin color, living in northern (Umeå) and southern (Malmö), Sweden. In order to achieve a moderate difference between groups (effect size 0.25) 20 children per group are required (power> 87%, alpha = 0.05). With an estimated dropout of 10%, a total of 220 children will be included. At baseline, the participants will undergo blood sampling for S-25(OH)D and other biomarkers, blood pressure and anthropometrical measurements, including bone densitometry and body composition using air displacement pletysmography, and the parents will answer a questionnaire on behavioral and emotional problems in the participating child using the Child Behavior Checklist. These measurements will be repeated at follow-up in February-March 2013.
The overall purpose of the study is to investigate whether there is a relationship between 26 different single nucleotide polymorphisms (SNPs) in the vitamin D pathway, ultraviolet B (UV-B) irradiation of the skin and vitamin D status. The hypothesis is that vitamin D status are influated by different genetic genotypes in the vitamin D pathway.
Background and Objectives : The presence of vitamin D deficiency in patients with type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD). We aim to see whether supplementation of vitamin D in these patients helps to improve the endothelial function (EF) a surrogate marker of CVD risk. Hypothesis: Vitamin D supplementation in patients with T2DM and low serum 25(OH) D concentrations (<30ng/ml) will improve EF as measured by the Endo-PAT machine by 0.4 units (30% improvement over baseline) and/or will result in a increase of EPCs (CD133+/KDR+) and CD45dim CD34+/KDR. The investigators will test this hypothesis by comparing 2 groups of T2DM patients randomized to placebo or vitamin D3 for 16 weeks. Methods: This is a 16 weeks trial in which 120 T2DM patients will be screened with the aim to recruit 60 T2DM patients with vitamin D deficiency or insufficiency. Out of these 60 patients , 30 patients will be started on vitamin D supplementation and 30 patients will be given a matched placebo. Endothelial function (EF) will be checked before and after supplementation to see a change in EF. Significance of Project: If this study shows a significant improvement of EF, it would justify larger scale studies to show that vitamin D supplementation in patients with T2DM mitigates CVD risk and vitamin D supplementation in patients with T2DM and vitamin D deficiency to improve CVD risk.