View clinical trials related to Vitamin D Deficiency.
Filter by:Children with Cystic Fibrosis, ages greater than and equal to 36 months of age and less than or equal to 18 years of age, with a 25OHD level less than 30 ng/dL will be asked to participate in this study. Upon consent, they will be given oral cholecalciferol supplementation of 250,000 IU during their next CF clinic visit. The safety will be assessed by measuring a serum calcium level within 1 week of supplementation. Efficacy will be assessed using repeated 25OHD levels throughout the course of 12 months. Feasibility will be assessed with the previous two measures as well as a brief questionnaire administered via telephone within 1 week of supplementation.
Aim: To investigate whether cholecalciferol (4800 U/daily) or placebo for 16 weeks reduces proteins levels associated with vascular calcification (osteoprotegerin, osteopontin, osteocalcin) in patients treated with peritoneal dialysis and 25(OH) vitamin D deficiency.
A randomized double blind placebo control trial study will be conducted in critically ill patients with vitamin D deficiency. Investigator aimed to study the effect of oral vitamin D3 supplementation, compare to placebo, on skeletal muscle mass and body composition.
Determine differences in serum vitamin D metabolism by genetic ancestry.
The objective of this study is to assess the effects of a high-dose vitamin D3 on the composition of gut and lung microbiota in adolescents and adults with cystic fibrosis who are vitamin D deficient.
To investigate possible physiologic interactions between the adrenal- and the parathyroid glands in patients with secondary hyperparathyroidism.
One in four infants are born with low amounts of vitamin D stored in their body. This study is designed to test whether improving vitamin D status quickly after birth helps infants to build muscle and to normalize growth. This is important since the investigators have noticed in previous work that infants with low vitamin D have higher body weight relative to body length later on and that those who develop very good stores quickly have a leaner body type. Therefore, in this study infants with low stores early after birth will be given either the regular amount of supplementation or a higher amount to more rapidly build up the vitamin stores in the body. Infants in both groups will be measured for muscle and fat mass at standardized ages during the first year of life and into the toddler years. The information will inform health care professionals and parents of the importance of establishing good vitamin D stores early in life. Vitamin D supplementation is a modifiable factor that is already recommended for all term born infants. Knowing how much is needed in infants born with low stores has not been tested in a controlled manner in Canada.
This randomized pilot early phase I trial studies how well cholecalciferol works in treating patients with newly diagnosed non-Hodgkin lymphoma or chronic lymphocytic leukemia with low levels of vitamin D (vitamin D deficiency). Cholecalciferol may increase levels of vitamin D and improve survival in patients with non-Hodgkin lymphoma or chronic lymphocytic leukemia receiving standard of care chemotherapy.
Total 25(OH)D is currently used as a biomarker of vitamin D status. However, there is some debate as to whether total 25(OH)D is the best marker to use. It has been suggested that free vitamin D may be better because it may be more biologically available. There are also some uncertainties about how we treat vitamin D deficiency. A single dose is attractive because it is certain that the patient has had the dose and there is no requirement for ongoing compliance, but it is still not clear what the best dose is to give. Also, recent studies have highlighted that high dose vitamin D supplementation may increase the risk of falling in older populations. The investigators believe that studying how free vitamin D responds to different bolus doses is the best way address some of the current research gaps, including what is the best biomarker of vitamin D status, what is the mechanism of vitamin D toxicity and what is a safe bolus dose to treat deficiency. The investigators will study changes in total and free 25(OH)D, and also clinical response, to three different bolus doses of vitamin D (50 000IU, 150 000IU and 500 000IU) in 84 vitamin D deficient postmenopausal women, over a three month period with 5 study visits. A concurrent control group of 28 vitamin D sufficient postmenopausal women will also be recruited. This will allow the investigators to determine how total and free vitamin D change with bolus dosing and whether there is a disproportionate rise in free 25(OH)D with higher doses that may lead to hypercalcemia and falls.
This meta-analysis will be conducted to study the effect on vitamin D supplements on markers for cardiovascular disease and diabetes using individual participant data from 12 RCTs. Given that previous data suggest that vitamin D supplementation might be most effective in those individuals with very low 25-hydroxyvitamin D (25(OH)D) and potentially harmful in those achieving very high levels after vitamin D supplementation, this meta-analyses will be performed in subgroups according 25(OH)D levels.