View clinical trials related to Vitamin D Deficiency.
Filter by:Hypothesis: 25-hydroxy vitamin D levels in non-itching hemodialysis (HD) patients will be higher than those in HD patients with itching 25-hydroxy vitamin D levels will be measured in non-itching hemodialysis patients and compared to levels previously measured in a previous study of 25-hydroxy vitamin D levels of patients complaining of itching.
The purpose of this research study is to determine whether taking vitamin D, every day, over a 12 week period will improve the vitamin D status, risks for poor heart health, risks for developing type 2 diabetes, and/or muscle strength in overweight, African American teenagers with low vitamin D levels.
The purpose of this research is to determine what supplemental doses of vitamin D may be necessary to raise serum levels to optimal levels and how vitamin D supplementation and changes in vitamin D status impact cardiovascular risk factors in schoolchildren.
Primary: to investigate tolerability of interventional high dose Vitamin D3 supplementation, titrated to reach serum levels near the high end of the reference range (30-100 ng/ml), in vitamin D deficient pediatric Autism Spectrum Disorder (ASD) patients. The study will determine if initial safety and effect estimates predict that a double blind randomized control trial (RCT) with a larger set of patients will be worthwhile in the localization of this treatment aimed at improving the symptoms of ASDs. Exploratory: to determine efficacy of high dose D3 replacement for improvement in the core symptoms of autism, including sociability, eye contact, anger outbursts, stimming behavior, and sleep, as determined by parental and clinical evaluation scales.
The importance of vitamin D (VitD) in the prevention and treatment of human health conditions has gained increased attention in recent years. As a result, medical providers of all categories are screening clinical VitD status frequently, yet become challenged with how to best advise patients regarding repletion of VitD status, i.e. which form of VitD replacement is most effective. It has been recognized that to achieve significant effects - serum concentrations >30ng/ml (75 nmol/ml) - it is necessary, as well as safe, to recommend substantially higher doses than were previously thought sufficient. These higher doses can be easily achieved orally. This clinical trial aims to compare absorption of three available forms of this fat-soluble vitamin, due to the potential differences in absorption of different preparations. High-quality powdered, chewable and lipid-emulsified VitD are readily available as supplements, yet these have not been systematically compared. This three-arm, randomized clinical trial will compare the difference in serum 25-hydroxycholecalciferol (25-OH)D concentration between the three arms at baseline and after random administration of one of the three VitD preparations for 12-weeks at a dosage of 10,000 IU VitD per day. The investigators hypothesize that the three forms of vitD will result in an equivalent increase in serum 25OHD.
The purpose of this study is to evaluate the absorption of dietary supplement of vitamin D3 (cholecalciferol), through the variation of 25 (OH) D levels, as the fat content of the meal associated with the administration of the supplement.
The purpose of the study is to compare the efficiency of UVB and vitamin D supplementation in treatment of vitamin D deficiency.
This study will examine whether the amount and type of fat, mono-unsaturated fat (MUFA) vs. poly-unsaturated fat (PUFA), in a meal affects the absorption of vitamin D, which is taken after that meal. The study hypothesis is that vitamin D3 absorption will be greater when fat is present vs. absent in the meal. A secondary hypothesis is that vitamin D3 absorption will be greater in the presence of a meal with a high MUFA/PUFA compared with a low MUFA/PUFA ratio.
The investigators would like to test the hypothesis that maternal vitamin D supplementation during lactation in dose 1200IU/d (400IU from multivitamins + 800 IU cholecalciferol) is more effective than 400IU/d (400IU from multivitamins + placebo)to built appropriate maternal vitamin D status and could be beneficial for maternal and infants bone mineralization and body composition (proper proportion of muscle and fat tissues in body weight) and is safe for both. The investigators also want to confirm that vitamin D supplementation of exclusively breastfed infants in dose 400IU/d is adequate to build appropriate vitamin D status independently of mother's vitamin D supplementation up to 1200 ID/d. Additionally the investigators hypothesize that because of changes in lifestyle there will be no substantial seasonal differences in vitamin D status of pregnant women at the delivery and their newborn infants.
The aim of this study is to investigate the bioavailability of vitamin D2 and D3 as measured by the increase of the specific hydroxy forms in serum (25(OH)D2 and 25(OH)D3, respectively, and by total 25(OH)D.