View clinical trials related to Vitamin D Deficiency.
Filter by:In the United States, ~1 million elective hip or knee replacement surgeries are performed annually. With estimated surgical site infection (SSI) rates as high as 2.5%, this represents ~25,000 patients at risk of potentially avoidable morbidity following lower extremity joint replacement surgery. Although SSIs only account for 20% of all HAIs, they are a major risk factor for prosthetic joint infections (PJIs). Furthermore, UTIs have also been identified as an independent risk factor for infections of implanted hardware. In general, the majority of PJIs become apparent within 3 months of hardware implantation, but deep infections may not be evident for up to one year after surgery. Hardware infections result in delayed healing, repeated surgical interventions, and long-term antibiotic therapy. PJIs are associated with an average increase in hospital LOS by 14 days, additional expenditures of up to $50,000 per infected joint, and a doubling of the mortality rate compared to uninfected lower extremity joint replacements. Recent work from our group suggests that vitamin D insufficiency may be a risk factor for perioperative HAIs. The prevalence of vitamin D insufficiency is approximately 40% in elective joint replacement surgery patients, and perioperative 25(OH)D levels drop 30-40% in the setting of surgical stress, remaining 20% below baseline up to 3 months after surgery. To date, perioperative vitamin D optimization strategies have not been reported. Therefore, our goal is to study the effect of a single (pre-operative) versus a divided (pre-operative and on post-operative day 1) dose of cholecalciferol on perioperative vitamin D status in patients scheduled for elective hip or knee joint replacement surgery.
The investigators hypothesize that native vitamin D will have more variability in 25(OH)D dose response when compared to a given equipotent dose of 25-hydroxyvitamin D3. This will be a single blind, active control, pharmacokinetic study of 625 μg 25(OH)D given orally or 2500 μg native vitamin D given orally.
Primary hyperparathyroidism (PHPT) is a common disease that occurs in 1 in 10,000 people every year. In the presence of this condition, the parathyroid glands produce excessive amounts of parathyroid hormone (PTH), which regulates calcium levels. The high levels of parathyroid hormone remove too much calcium from bones, and then deposit the excess calcium in the blood, which is then filtered into the urine by the kidneys. Bone health is threatened by excess calcium loss which weakens bone structure. Other affected organs include the skeleton (calcium loss leads to a "weakening" of the skeleton), and the kidneys (high blood calcium can lead to kidney stones). It is now evident that the majority of patients with even mild Primary Hyperparathyroidism are vitamin D deficient. In 2009, new international guidelines for the management of asymptomatic PHPT direct physicians to measure 25-hydroxyvitamin D (D3 or 25-OHD) in all patients, and to replete the reserve of vitamin D when the level is low (< 20 ng/ml). However, no recommendations for vitamin D repletion are given, because of limited data regarding the effects of vitamin D repletion, appropriate dosing and safety. Therefore, there is an urgent need for data upon which to base such recommendations, as well as are data on the effects of such treatment upon bones. Subjects with low vitamin D3 levels will be selected for this trial. They will be given enough vitamin D3 to raise their low blood levels from a low to a normal range. The assessments in this study, including the quadruple label bone biopsy, will allow us to document the short term effects of administering vitamin D3 on changes in bone. All participants enrolled in this trial will be vitamin D3 deficient. Participants will take an antibiotic (tetracycline) 4 times a day to mark the starting point from which bone changes will be assessed. After 3 days of tetracycline, a 12 week course of vitamin D3 or placebo will be initiated. Six of 7 participants will receive the study drug (active vitamin D3), while 1 in 7 will receive a placebo (sugar pill). Ten weeks later, another 3-day course of tetracycline will be given. At the end of 12 weeks, a bone biopsy will be done. A small piece of bone (about the size of a pencil eraser) will be removed from the hip (iliac crest). The bone will be analyzed to determine the effect of vitamin D3 on primary hyperparathyroidism. There will be 4 study visits: Screening, Baseline, Week 8, and Week 12 when the bone biopsy will be performed. Study Procedures: Medical and Social History Blood tests (drawn at the study center and local Quest Lab) 24-Hour urine collection for calcium and creatinine excretion Abdominal X-ray (to assess for kidney stones) Transiliac crest Bone Biopsy
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.
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.
This is a feasibility study to examine the treatment with Metformin, vitamin D with calcium supplement for insulin resistance in obese, black, female teens. The association of low vitamin D levels and decreased insulin sensitivity has been established. Thus, the specific aims of this study are: Specific aim 1: To examine the effect of an 8-week treatment with vitamin D and calcium supplementations on diabetes-related risk factors in obese, black, female teens. Hypothesis 1a: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with vitamin D and calcium supplementation will significantly improve measures of insulin resistance and sensitivity (as determined by the homeostatic model assessment for insulin resistance and whole body insulin sensitivity index measures) when compared to controls not receiving vitamin D and calcium. Hypothesis 1b: In obese, black teen females with both insulin resistance and vitamin D deficiency, treatment with vitamin D and calcium supplementation will significantly improve measures of cardiovascular disease (decreased BMI and improved triglycerides and LDL) when compared to controls not receiving vitamin D and calcium. Specific aim 2: To determine if the addition of Metformin to the 8-week treatment with vitamin D and calcium supplementations improves diabetes-related risk factors in obese, black, female teens. Hypothesis 2a: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with Metformin, vitamin D, and calcium supplementation will significantly improve measures of insulin resistance and sensitivity (as determined by the homeostatic model assessment for insulin resistance and whole body insulin sensitivity index measures) when compared to standard of care or treatment with vitamin D with calcium supplementation alone while controlling for dietary intake of vitamin D and calcium. Hypothesis 2b: In obese, black, female teens with both insulin resistance and vitamin D deficiency, treatment with Metformin, vitamin D, and calcium supplementation will significantly improve measures of cardiovascular disease risk (as determined by the decreased BMI, improved triglycerides and LDL) when compared to standard of care or treatment with vitamin D with calcium supplementation alone while controlling for dietary intake of vitamin D and calcium.
The human immune system produces a protein called hCAP18 (also known as LL-37 or cathelicidin). This protein is believed to help the body to fight infections. Studies suggest that vitamin D may important in the production of hCAP18. This study is designed to test the ability of two different forms of vitamin D to affect levels of hCAP18. Vitamin D and hCAP18 levels will be measured during an initial visit. Individuals who are vitamin D deficient will be randomly assigned to receive one of two forms of vitamin D for two weeks. After this, follow-up levels will be measured.
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%.
Other studies suggest that low Vitamin D levels may contribute to musculoskeletal pain. Hypothesis: Administration of oral Vitamin D supplements will improve vague musculoskeletal pain in children.
While vitamin D supplementation is safe and effective in repleting vitamin D levels in dialysis patients, the impact on anemia is unknown. The majority of hemodialysis patients require erythropoietin supplementation to maintain their serum hemoglobin between 11 and 12 gm/dL, a drug that is both costly and associated with significant side effects. If repletion of vitamin D significantly decreases erythropoietin requirements in hemodialysis patients, it would result in a substantial reduction in patient care costs. Our aim is to study the impact of ergocalciferol supplementation in hemodialysis patients with 25-hydroxyvitamin D deficiency. The investigators anticipate approximately 30% reduction in erythropoietin dose requirement in our hemodialysis population.