The Effect of Weight on Vitamin D Dose Response
ObesityVitamin D DeficiencyVitamin 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.
A Study on Oral Vitamin D Megadoses
Hypovitaminosis DThe 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.
Effect of Vitamin D Oral Supplements on 25 OH Vitamin D Levels
Vitamin D DeficiencyVitamin 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.
Vitamin D Supplementation and Metabolism in Vitamin D Deficient Elderly
Vitamin D DeficiencyMetabolic SyndromeThe 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.
African American Children, Glycemic Control, and Type 2 Diabetes
Type 2 DiabetesVitamin D DeficiencyUsing 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.
DAYLIGHT: Vitamin D Therapy in Individuals at High Risk of Hypertension
HypertensionVitamin D Deficiency1 moreThis is a randomized, double-blind, multicenter, 6-month follow-up trial of low (400 IU/day) versus high (4000 IU/day) dose vitamin D supplementation in individuals with pre- and early stage 1 hypertension and vitamin D deficiency. A total of 530 participants (265 participants per treatment arm) will be randomized between 3 sites. Approximately 2,250 participants will be screened between the 3 sites. Vital signs, 24-hour ambulatory blood pressure monitoring, clinical laboratory safety tests and adverse event assessments will be performed to evaluate the effectiveness of the two doses of vitamin D on blood pressure. Blood samples will be stored for future biomarker assessments. The total duration of the study is anticipated to be 18 months, assuming a 12 month enrollment period.
Vitamin D Repletion in Primary Hyperparathyroidism
Primary HyperparathyroidismVitamin D DeficiencyThis 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.
Cholecalciferol (Vitamin D3) Therapy in Chronic Kidney Disease (CKD) Subjects
Chronic Kidney DiseaseVitamin D DeficiencyThis is a 12 week pilot and feasibility study with an enrollment goal of 30 subjects. Half of the subjects will be randomized to vitamin D3 and the other half will receive a placebo. Subjects will be referred from the nutrition or renal clinic at Emory. CKD stage 3 and 4 patients will be eligible for participation if they have been determined to have vitamin D deficiency and are not on treatment with vitamin D or vitamin D analogues. Subjects will sign an informed consent form after reviewing the protocol in detail with the principal investigator. A questionnaire would collect information about dietary vitamin D intake, sunlight exposure, and any symptoms of vitamin D deficiency. The subject will have baseline levels of serum vitamin D (25-hydroxyvitamin D), parathyroid hormone (PTH), serum calcium and phosphate, creatinine and other markers of bone turnover. The questionnaires and the blood draws would be repeated on the 6th and 12th week of the study. Subjects will be given 12 pills of each containing either 50,000 IU vitamin D or placebo and asked to take one pill a week. They would be scheduled to return to the clinic after 6 weeks and blood measurements would be repeated. Subjects will be asked to revisit for their final visit at the 12th week when they would have their last blood draw and assessment.
High vs Low Dose Vitamin D in Patients With Diabetic Peripheral Neuropathy
Diabetes Type 2Diabetic Neuropathies1 moreAim. To assess the effect of different doses of vitamin D supplementation on peripheral neuropathy in patients with type 2 diabetes mellitus (T2DM). 68 patients with T2DM and peripheral neuropathy will be randomized into two treatment groups: cholecalciferol 5,000 IU once/week and cholecalciferol 40,000 IU once/week orally for 24 weeks. Severity of neuropathy (neuropathy symptom score (NSS), neuropathy disability score (NDS), visual analog scale (VAS)), body mass index (BMI), glycated hemoglobin (HbA1c), 25-hydroxycalciferol (25(OH)D), parathyroid hormone (PTH), serum interleukins (IL) 1β, 6 and 10, C-reactive protein, tumor necrosis factor α and microcirculation (MC) parameters assessed before and after treatment. The initial and final indicators of the skin blood flow (M, σ, Kv) and MC parameters after postural and occlusal tests by laser Doppler flowmetry (LDF). Sixteen subjects without diabetes will represent the control group.
Immunomodulating Effects of Supplementation With 25-OH Vitamin D
Vitamin D DeficiencyScleroderma1 moreIntroduction. The thickening fibrotic of the skin in systemic sclerosis (SSc) could reduce endogenous availability of Vitamin D by sun exposition. Vitamin D hypovitaminosis have been described in high prevalence in autoimmune disease as SSc. The cholecalciferol contributes to improve the balance TH1/Th2/Treg in favor anti-inflammation and anti-fibrotic profile. Aim. to analyze the effect(s) of short-term cholecalciferol supplementation on cytokine profile in Th1, Th2, and Treg cells subpopulations in SSc patients. Method. Randomized clinical trial conduct in patients with SSc (ACR-EULAR 2015) who signed informed consent. General characteristics, severity of organ involvement scored by Medsger disease severity scale (MsDSS) and cytokine Th1, Th2 and Treg will be determinate. All data will be analyzed using SPSS software. It will be used parametric statistics for normally distributed variables and nonparametric statistics for free distribution.