Active clinical trials for "Vitamin D Deficiency"

The purpose of this study is to examine the effects of Vitamin D supplementation on the reasons (mechanisms) underlying the development of type 2 diabetes, metabolic syndrome (high blood pressure, cholesterol, diabetes, body weight/obesity), muscle weakness and wasting (sarcopenia), and impaired physical function (poor balance and walking) associated with vitamin D deficiency and osteopenia/osteoporosis (bone loss). The investigators obtain vitamin D through our diet and sunlight, and its conversion to active vitamins in the liver and kidneys promotes the intestinal absorption of calcium and regulation of bone growth. Therefore, vitamin D deficiency has been known for years to lead to weakened bones (osteopenia and osteoporosis). However, more recently, studies show vitamin D deficiency is associated with a number of other diseases, including type 2 diabetes, muscle weakness, frailty, and the metabolic syndrome. It has also been associated with cognitive impairment. Diabetes affects multiple organ systems including the heart, kidneys, musculoskeletal and nervous system. The possibility that vitamin D deficiency is linked to the development of type 2 diabetes, metabolic syndrome, muscle weakness and wasting (sarcopenia) and osteopenia/osteoporosis, and that vitamin D supplementation decreases the risk for these diseases, provides a relatively easy/accessible and inexpensive model of preventive therapy to decrease the incidence of these diseases. In addition, it is likely that genetic (inherited) factors play a role, but the relationship of these genes to these metabolic abnormalities have not been elucidated. Understanding the role of Vitamin D in health will allow us to translate these findings into therapy.

Vitamin D3 is a vitamin that is an essential component of biological regulating systems in humans. Sun exposure is the predominant source of vitamin D3. Previous research has shown that vitamin D3 deficiency is common worldwide. It is especially common in northern countries with long winters due to inadequate sun exposure during winter. In the US, an estimated 36% to 57% of healthy middle-aged to elderly adults have vitamin D3 deficiency. Current research indicates that obesity is associated with a low vitamin D3 level.

Using a randomized, placebo-controlled trial design in subjects with vitamin D deficiency, the investigators propose to determine if vitamin D treatment improves glycemic control in vitamin D deficient subjects with T2DM. The investigators hypothesize that oral vitamin D treatment will improve glycemic control and ß-cell function in vitamin D deficient AA subjects with T2DM. The investigators further hypothesize that maintaining serum 25(OH)D concentrations above 20 ng/ml with oral supplementation of vitamin D will have additional glycemic control effects.

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.

This study will look at the effect of 2 treatment regimens that contain vitamin D in a six-month treatment trial of patients with PHPT who are vitamin D deficient. Patients will be assigned randomly to one of 2 regimens, and will be followed with tests of their blood, urine and bones. This study should provide important information on the effect of vitamin D therapy in patients with PHPT. In addition, data from this study will guide physicians as to how best to treat their patients who have PHPT and vitamin D deficiency.

The purpose of this study is to determine if infrequent administration of oral vitamin D megadoses is effective treatment to maintain serum 25-hydroxyvitamin D(3) above target levels of 50-75 nmol/L. The investigators hypothesize that 100 000 IU or at least 200 000 IU vitamin D3 in every three months would be effective and safe treatment to achieve the target levels.

This study aims to answer the question whether oral vitamin D supplementation can decrease lung complications in children and adolescents with sickle cell disease. Lung complications are the leading causes of morbidity and of death in sickle cell disease. Infections and increased inflammation play important roles in the development of the lung problems in sickle cell disease. Emerging evidence shows that vitamin D helps the immune system to fight infection and to control inflammation and could potentially help prevent respiratory complications in patients with sickle cell disease. The investigators hypothesize that oral vitamin D3, 100,000 IU (2.5 mg), given once a month to a group of children and adolescents with sickle cell disease, will reduce the rate of respiratory events (infection, asthma exacerbation and acute chest syndrome) compared to the rate in a group given standard dose oral vitamin D3, 12,000 IU (0.3 mg) given once a month. Funding Source - U.S. Food & Drug Administration, Office of Orphan Products Development

Vitamin D is essential to bone health. In Canada, it is obtained by sunlight exposure of the skin (between April and October) or by a few foods such as fatty fish, eggs or fortified milk and margarine. This study has 3 main goals which are to determine if Veteran's have enough vitamin D stored in their body, if adding a supplement of 2000 IU/d is enough to correct low vitamin D stores and, if specially formulated foods using an approved vitamin D supplement, are appropriate to maintain vitamin D stores in relation with functional and cognitive status. Initially, a 2000 IU supplement of vitamin D will be provided for 8 weeks. After this period, the participants will be randomly separated into 3 groups (Group A, B or C) for a period of 24 weeks. Group A will receive their usual menu. Group B will receive their usual menu with 1 portion of food containing 500 IU of added vitamin D. Group C will receive their usual menu with 1 portion of food containing 1000 IU of added vitamin D. Food intake will be assessed every 8 weeks and blood samples will be taken every 4 weeks to monitor change in blood concentration of vitamin D and other indicators of bone health. The investigators will document weight and height, hand grip strength, the mid-arm and mid-calf circumferences, the capacity to perform activities of daily living, the number of prescriptions and changes in health condition. The investigators will also take an X-ray the tibia and upper arm to document the amount and quality of bones in those regions. A total of 60 veterans of Ste-Anne's Hospital will participate in this study. Knowing more about vitamin D status and intake will help in confirming the required vitamin D recommendations for the elderly men living in long-term care institutions.

To evaluate the pharmacokinetic parameters of orally administered 25-hydroxyvitamin D3 [25(OH)D3] and vitamin D3 from the corresponding serum concentration-time curves in healthy adults and adults with a history of intestinal malabsorption.

Introduction. Vitamin D regulates mineral metabolism. Its deficiency has been associated with diabetes, cancer and increased mortality. 25OH vitamin D (25VD) is stable and suitable for the evaluation of vitamin D sufficiency. The aim of the study is to evaluate whether cholecalciferol supplementation for a period of 12 weeks can normalize decreased 25VD levels and reduce increased parathormone (iPTH) in hemodialysis (HD) patients with a vitamin D deficiency. Secondary aims: to evaluate decrease in inflammation, anemia or use of erythropoietin. Design. Randomized, double blind clinical trial in two arms of HD patients with 25OH Vitamin D deficiency and secondary hyperparathyroidism, for a period of 12 weeks. Population. Patients over 18 years of age on HD for more than 3 months and levels of 25VD < 30 ng / ml and iPTH >300 ng/ml , who sign a consent form. Randomization will be achieved by using a table of random numbers at the pharmacy, and neither doctors nor patients will know which group they have been assigned to. Treatment. Supplementation will consist of one 5000 IU cholecalciferol tablet or placebo during dialysis for a period of 12 weeks. Monthly monitoring will include: haemoglobin (g/dl), Calcium (mg/dl), Phosphorous (mg/dl), PTH (ng/ml), epo dose (IU/kg/week), epo resistance (IU/kg/week/g Hb). At the beginning and end of the study the following will be measured: alkaline Phosphatase (IU/ml), PCR (mg/L), 25VD (ng/ml), ferritin (ng/ml) and transferrin saturation, quality of life (SF36). During the study, doses of calcitrol or paricalcitol will not be modified. The study will be discontinued if calcemia ≥ 10.5 mg/dL is detected on two occasions. Size of sample is estimated at 120 patients for a PTH decrease of 20% in 35% of patients in group treated (assuming 15% follow-up losses). Analysis will be done for Intention to treat for the primary outcome. Ethical aspects: Authorization has been obtained from the Ethics Committee of the institution as regards Good Clinical Practices, Helsinki Declaration and national regulations. The trial will be registered at the Ministry of Health.