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.

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 world wide. 25 OH vitamin D level is the best indicator of vitamin D status. The determination of the appropriate dose of vitamin D supplement is essential for management of vitamin D deficiency as well as for designing vitamin D fortification programs. The increments in 25 OH vitamin D levels following various doses of vitamin D supplement for different genders, body weights, and starting 25 OH vitamin D level have not been well defined. The time course of depletion of repleted vitamin D stores is also not known. The investigators plan to conduct a double blind randomized study on 9 cohorts to determine levels of 25 OH vitamin D following supplementation with different doses of vitamin D3 for 5 months and their withdrawal for 3 months.

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

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%.

It is the investigators hypothesis that the current method of evaluating vitamin D status, measuring circulating 25-hydroxy vitamin D is not providing the full metabolic picture, and is therefore inadequate. The investigators liken this concept to the evolution of cholesterol where initially, total cholesterol was the only measurement, and have since determined the importance of HDL, LDL and triglycerides in evaluating patient status. Similarly, the investigators feel measurement of other vitamin D components such as sulfated vitamin D, circulating vitamin D3 and 3-epi 25-hydroxy vitamin D will offer more comprehensive information about a patient's vitamin D status. It is our overarching hypothesis that a "vitamin D assay panel," will enhance understanding of vitamin D status. It is our expectation that the enhanced understanding based on improved measurement capability will ultimately translate to improved definition of vitamin D status and need for supplementation on an individual level.

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.

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.

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