Active clinical trials for "Vitamin D Deficiency"

This study was intended to evaluate the effect of vitamin D supplementation on insulin sensitivity and pancreatic islet beta-cell function. Our hypothesis was that vitamin D supplementation to normal levels in patients with impaired fasting glucose will result in improved insulin sensitivity and improved beta cell function.

Patients with chronic kidney disease (CKD) have a higher mortality rate than the general population, with cardiovascular disease (CVD) accounting for approximately 50% of deaths. Vascular calcification is a common finding in patients with CKD. Furthermore, patients with CKD develop secondary hyperparathyroidism, partly because of a decrease of calcitriol synthesis on the kidney. Treatment of secondary hyperparathyroidism includes use of activated vitamin D including calcitriol and paricalcitol. Recent evidence in dialysis patients suggest an improved survival in patients using paricalcitol compared to calcitriol. Studies in uremic rats suggests that there are differential effects of calcitriol and paricalcitol in expression of markers of soft-tissue calcification independent of calcium-phosphorus product. Calcitriol increased calcification of vascular smooth muscle cells cultured in calcification media. There was also significant increase in pulse pressure in animals treated with calcitriol. The investigators hypothesize that these different forms of vitamin D may have differential effects in vascular calcification progression in CKD patients.

Childhood Lead Poisoning is a widespread disease that has few effective treatments. The specific aims of this proposed clinical trial are threefold: To determine whether a six-week course of a newly formulated d-penicillamine suspension will effectively reduce blood lead level in children aged 6 months to 16 years with blood lead levels of 15-25 μg/dL. To determine whether d-penicillamine chelation produces a sustained reduction in blood lead level in comparison with succimer and other lead chelators which always produce a significant post-treatment "rebound". To determine whether chelation with d-penicillamine improves the physiologic disturbances that can be measured in children with blood lead levels in this range.

Vitamin D deficiency is common in cystic fibrosis. Vitamin D deficiency frequently persists despite aggressive treatment with ergocalciferol, a vitamin D preparation also known as vitamin D2. Cholecalciferol, a vitamin D preparation also known as vitamin D3,may work better to increase vitamin D levels. Vitamin D is important for absorption of calcium from the diet and bone health. Vitamin D more recently has been found to play a role in regulating the normal inflammatory process. Since cystic fibrosis is a state of excessive inflammation, vitamin D may be playing a role in cystic fibrosis. We hypothesize: cholecalciferol will work better to increase vitamin D levels in patients iwth cystic fibrosis and that it will have an effect on markers of inflammation.

The investigators hypothesize that a 3 month course of vitamin D supplementation to treat 25(OH)D deficiency in stone formers with high levels of 24-hour urinary calcium will not increase urinary calcium excretion by greater than 10%.

The optimal dose of vitamin D needed to optimize beneficial effects on musculoskeletal outcomes remains to be defined. Equally unclear is the impact of vitamin D on fuel metabolism and insulin sensitivity in human subjects. Thus, the overall objective of this proposal is to test the hypothesis that in ambulatory overweight elderly individuals, vitamin D administration at doses higher than currently recommended will: Have a salutary effect on parameters of glucose and fuel metabolism. It will thus decrease indices of insulin resistance, improve lipid profile, and decrease markers of cardiovascular disease including adipokines, inflammatory cytokines, and markers of cell adhesion. Have a superior effect on indices of mineral and musculoskeletal metabolism, including bone remodeling markers, lean mass, and bone mineral density. We will investigate whether this effect is modulated by entry status of vitaminD and PTH as detailed below

Vitamin D inadequacy continues to be neglected in nursing home residents. We hypothesized that part of this neglect is due to absence of data documenting safe and effective ways to replete this inadequacy.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in reproductive age women, which causes disordered follicle growth and ovulation resulting in infertility. In addition women with PCOS have hyperandrogenemia and a dysregulated hormonal profile, resulting in altered feedback on the hypothalamic-pituitary-gonadal (HPG) axis. Obesity, insulin resistance, vitamin D (VD) deficiency and ageing worsen the symptoms. The gonadotrophins - follicle stimulating hormone (FSH) & luteinising hormone (LH), along with the pregnancy hormone human chorionic gonadotrophin (hCG) have structural similarities. The altered levels of FSH and LH in women with PCOS cause production of hCG from the brain leading to false positive pregnancy tests. Part one of this project will involve the investigation of this over-production of hCG in urine and serum of women with PCOS to develop suitable ovulation and pregnancy test kits, in collaboration with Swiss Precision Diagnostics (SPD). In Part two of the project, we would like to see if intervention with VD supplementation and/or using myo-inositol supplement compared with metformin (insulin sensitiser), improves prediabetes, distribution of fat/water content, weight loss and menstrual cyclicity in women with PCOS. We aim to correlate these interventions with particular serum & urine markers to develop better diagnostic tools.

This study will evaluate the effect of vitamin D supplementation on the neurocognitive function of older people with lower than normal levels of vitamin D at baseline

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), are chronic relapsing inflammatory conditions of the gastrointestinal tract. IBD is thought to result from a complex interaction between genetic, immune, microbial and environmental factors. There is emerging data suggesting Vitamin D may not only play a role in bone health but may also be involved in gut health as well. While there are guidelines regarding the recommending doses of Vitamin D for supplementation and maintenance in bone health, these strategies are unknown in those with inflammatory bowel disease. The investigators seek to determine a dosing strategy for this population using doses within the recommended guidelines for bone health.