BACKGROUNDObservational studies support an association between a low blood 25-hydroxyvitamin D level and the risk of type 2 diabetes. However, whether vitamin D supplementation lowers the risk of diabetes is unknown.
METHODSWe randomly assigned adults who met at least two of three glycemic criteria for prediabetes (fasting plasma glucose level, 100 to 125 mg per deciliter; plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter; and glycated hemoglobin level, 5.7 to 6.4%) and no diagnostic criteria for diabetes to receive 4000 IU per day of vitamin D 3 or placebo, regardless of the baseline serum 25-hydroxyvitamin D level. The primary outcome in this time-to-event analysis was new-onset diabetes, and the trial design was event-driven, with a target number of diabetes events of 508.
RESULTSA total of 2423 participants underwent randomization (1211 to the vitamin D group and 1212 to the placebo group). By month 24, the mean serum 25-hydroxyvitamin D level in the vitamin D group was 54.3 ng per milliliter (from 27.7 ng per milliliter at baseline), as compared with 28.8 ng per milliliter in the placebo group (from 28.2 ng per milliliter at baseline). After a median follow-up of 2.5 years, the primary outcome of diabetes occurred in 293 participants in the vitamin D group and 323 in the placebo group (9.39 and 10.66 events per 100 person-years, respectively). The hazard ratio for vitamin D as compared with placebo was 0.88 (95% confidence interval, 0.75 to 1.04; P = 0.12). The incidence of adverse events did not differ significantly between the two groups.
CONCLUSIONSAmong persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D 3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; D2d ClinicalTrials.gov number, NCT01942694.)A BS TR AC T
IMPORTANCE Overweight and obesity have been associated with adverse health effects. OBJECTIVE To systematically review evidence on benefits and harms of behavioral and pharmacotherapy weight loss and weight loss maintenance interventions in adults to inform the US Preventive Services Task Force.
SummaryThe Women's Health Initiative (WHI) double-blind, placebo-controlled clinical trial randomly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D3 daily or placebo, with average intervention period of 7.0 years. The trial was designed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture, and secondarily, total fracture and colorectal cancer.IntroductionThis study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data, with emphasis on fractures, cardiovascular disease, cancer, and total mortality.MethodsWHI calcium and vitamin D randomized clinical trial (CT) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation, and these data were contrasted and combined with corresponding data from the WHI prospective observational study (OS).ResultsAmong women not taking personal calcium or vitamin D supplements at baseline, the hazard ratio [HR] for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 (95 % confidence interval (CI), 0.38–1.00). In combined analyses of CT and OS data, the corresponding HR was 0.65 (95 % CI, 0.44–0.98). Supplementation effects were not apparent on the risks of myocardial infarction, coronary heart disease, total heart disease, stroke, overall cardiovascular disease, colorectal cancer, or total mortality, while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive.ConclusionThough based primarily on a subset analysis, long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women. Other health benefits and risks of supplementation at doses considered, including an elevation in urinary tract stone formation, appear to be modest and approximately balanced.Electronic supplementary materialThe online version of this article (doi:10.1007/s00198-012-2224-2) contains supplementary material, which is available to authorized users.
Older men with low bioE2 or high SHBG levels are at increased risk of nonvertebral fracture. When SHBG levels are high, men with low bioT levels have higher risk. The strongest association occurred when all measures were considered in combination.
Objective: To The prevalence of 25 hydroxyvitamin D [25(OH)D] deficiency, defined as 25(OH)D level less than 20 ng/mL, is high, especially among the elderly, with 25% to 65% affected. [1][2][3][4][5][6] While much research has focused on the adverse effect of 25(OH)D deficiency on bone health, 5,7 associations between 25(OH)D deficiency and non-bone health outcomes, including hypertension, 8 cardiovascular morbidity, 9 diabetes, 10,11 and cancer, 12,13 have also been reported. In addition, there is a growing body of literature to support the role of vitamin D in brain function and development.14 -25 Despite the experimental and animal evidence supporting an important role for vitamin D in mood and cognition, epidemiologic studies testing this hye-Pub ahead of print on November 25, 2009, at www.neurology.org.
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