Project description:BackgroundFalls occur frequently among older individuals, leading to high morbidity and mortality. This study was to assess the efficacy of vitamin D in preventing older individuals from falling.MethodsWe searched the PubMed, Cochrane Library, and EMBASE databases systematically using the keywords "vitamin D" and "fall" for randomized controlled trials (RCTs) comparing the effects of vitamin D with or without calcium supplements with those of a placebo or no treatment on fall incidence in adults older than 50 years. A meta-analysis was performed to calculate risk ratios (RRs), absolute risk differences (ARDs) and 95% CIs with random-effects models.ResultsA total of 38 RCTs involving 61 350 participants fulfilled the inclusion criteria. Compared with placebo, high-dose vitamin D (≥ 700 IU) can prevent falls [RR, 0.87 (95% CI 0.79 to 0.96); ARD, -0.06 (95% CI, -0.10 to -0.02)]. Low-dose vitamin D (<700 IU) was not significantly associated with falls. Subgroup analysis showed that supplemental calcium, 25(OH) D concentration and frequency influenced the effect of vitamin D in preventing falls. Sensitivity analysis showed that vitamin D prevented falls, which was consistent with the primary analysis. In addition, the active form of vitamin D also prevented falls.ConclusionIn this meta-analysis of RCTs, doses of 700 IU to 2000 IU of supplemental vitamin D per day were associated with a lower risk of falling among ambulatory and institutionalized older adults. However, this conclusion should be cautiously interpreted, given the small differences in outcomes.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42020179390.
Project description:BACKGROUND:Observational 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. METHODS:We 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 D3 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. RESULTS:A 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. CONCLUSIONS:Among persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D3 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.).
Project description:This article reviews the current literature addressing the treatment of schizophrenia with vitamin supplementation. It describes the important roles that vitamins play in normal metabolism, and reviews the evidence pertaining to vitamin deficiency and supplementation in patients with schizophrenia. There is mounting evidence suggesting that vitamin supplementation, in particular with folic acid, vitamin B12 and vitamin D, may be important in treatment within certain subgroups of patients. There is a need for larger randomized controlled trials, and further studies examining the incidence of schizophrenia in countries with poor prenatal care and malnutrition, as well as in countries that have adopted mandatory folic acid fortification of grain products, are recommended.
Project description:Vitamin A administration may decrease any stage of retinopathy of prematurity (ROP) in preterm infants. To evaluate whether vitamin A oral supplementation could be preventive in ROP incidence and severity in VLBW infants, we compared results from 31 preterm infants, (< 1500 g or < 32 weeks) who, during a previous investigation, prospectively received 3000 UI/kg/die oral retinol palmitate drops, for 28 days, with 31 matching preterm newborns hospitalized in our NICU the same period, as control group. Although ROP incidence was similar, in the supplemented group, we had 9 cases of ROP grade 1, no ROP grade ≥ 2, in the un-supplemented group, 4 cases of ROP grade 1 and 6 ROP grade ≥ 2 (p = 0.018). The percentage of babies requiring treatment for ROP was 0 in treated and 16.6 in the un-treated group (p = 0.020). Moreover, Vitamin A administration showed a protective effect with an 88% risk reduction of developing severe ROP. Since vitamin A parenteral/IM administration presents some awareness, the results of this investigation may be important to plan further trials to confirm the usefulness of oral administration in mitigating the ROP severity of VLBW infants.ClinicalTrials.gov NCT02102711; may 03/06/2014.
Project description:Congenital malformations are a common adverse outcome in pregnancies complicated by pregestational obesity, although the underlying mechanisms are still unrevealed. Our aim was to study the effect of oxidative stress in obesity-induced teratogenesis. Wistar rats were fed a high-fat diet for 13 weeks, with (OE group) or without (O group) vitamin E supplementation. Then, rats were mated and sacrificed at day 11.5 of gestation. Embryos from O dams presented a 25.9 ± 3.5% rate of malformations (vs. 8.7 ± 3.4% in C rats), which was reduced in the OE group (11.5 ± 2.3%). Pregestational obesity induced hepatic protein and DNA oxidation and a decline in antioxidant enzymes. Importantly, glutathione content was also decreased, limiting the availability of this antioxidant in the embryos. Vitamin E supplementation efficiently maintained glutathione levels in the obese mothers, which could be used in their embryos to prevent oxidation-induced malformations. To test the effect of decreasing glutathione levels alone in a cell culture model of neuroepithelium, murine embryonic stem cells (ESC) were induced to form neuronal precursors and glutathione synthesis was inhibited with the gamma-glutamylcysteine synthesis inhibitor, buthionine sulfoximine (BSO). BSO inhibited the expression of Pax3, a gene required for neural tube closure that is also inhibited by oxidative stress. Taken together, our data indicate that obesity causes malformations through the depletion of maternal glutathione, thereby decreasing glutathione-dependent free radical scavenging in embryos, which can be prevented by vitamin E supplementation.
Project description:Evidence on biological plausibility from mechanistic studies and data from observational studies suggest that vitamin D may be linked to risk of several types of cancer. However, evidence from clinical trials evaluating the effect of vitamin D supplementation on cancer risk is limited. The Vitamin D and Type 2 Diabetes (D2d) study is a multi-center, randomized, placebo-controlled clinical trial conducted to examine the causal relationship between oral vitamin D supplementation and development of diabetes among overweight adults with prediabetes. The D2d study provides a unique opportunity to assess the effect of vitamin D supplementation at a higher dose (4000?IU/day) than has been used in other clinical trials with cancer outcomes, in a population at higher than average risk for cancer. This paper provides: Krishnan and Feldman (2011) a) baseline characteristics of the D2d population included in the D2d cancer outcomes secondary study (D2dCA) and comparison to other large trials of vitamin D supplementation and cancer risk; Leyssens et al. (2013) b) description of data that are being collected during the trial and the planned statistical analyses to test whether vitamin D supplementation at a dose of 4000?IU/day has an effect on incident cancer overall, on incidence of certain types of cancer, and on incidence of precancerous lesions. Results of D2dCA will help guide future research and clinical recommendations related to vitamin D and cancer risk.
Project description:BackgroundPneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily zinc supplements have been reported to prevent acute lower respiratory tract infection (LRTI) and reduce child mortality. This is an update of a review first published in 2010.ObjectivesTo evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.Search methodsWe searched CENTRAL (Issue 21 October 2016), MEDLINE (1966 to October 2016), Embase (1974 to October 2016), LILACS (1982 to October 2016), CINAHL (1981 to October 2016), Web of Science (1985 to October 2016) and IMSEAR (1980 to October 2016).Selection criteriaRandomised controlled trials (RCTs) evaluating zinc supplementation for the prevention of pneumonia in children aged from 2 months to 59 months.Data collection and analysisTwo review authors independently assessed trial quality and extracted data.Main resultsWe did not identify any new studies for inclusion in this update. We included six studies that involved 5193 participants.Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (fixed-effect risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, six studies, low-quality evidence) and prevalence of pneumonia by 41% (random-effects RR 0.59; 95% CI 0.35 to 0.99, one study, n = 609, low-quality evidence). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (fixed-effect RR 0.79; 95% CI 0.0.71 to 0.88, four studies, n = 3261), but had no effect on lower specificity pneumonia case definition (i.e. age-specific fast breathing with or without lower chest indrawing) (fixed-effect RR 0.95; 95% CI 0.86 to 1.06, four studies, n = 1932).Authors' conclusionsZinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia.
Project description:ObjectiveTo evaluate the evidence of the supplements vitamin C and vitamin E for treatment and prevention of cancer.MethodsSystematic review of trials and meta-analysis. DATA SOURCES AND MAIN RESULTS: Thirty-eight studies showed scant evidence that vitamin C or vitamin E beneficially affects survival. In the ATBC Cancer Prevention Study Group, no statistically significant effect of treatment was seen for any cancer individually, and our pooled relative risk (regardless of tumor type) for alpha-tocopherol alone was 0.91 (95% confidence interval [CI]: 0.74, 1.12). All cause mortality was not significant. In the Linxian General Population Trial, the relative risks for cancer death for vitamin C (combined with molybdenum) was 1.06 (95% CI: 0.92, 1.21) and for vitamin E (combined with beta-carotene and selenium) was 0.87 (95% CI: 0.76, 1.00). We identified only 3 studies that reported statistically significant beneficial results: vitamin C (in combination with BCG) was found to be beneficial in a single trial of bladder cancer and vitamin E (in combination with omega-3 fatty acid) increased survival in patients with advanced cancer. In the ATBC trial, in analyses of 6 individual cancers, the prevention of prostate cancer in subjects treated with alpha-tocopherol was statistically significant (RR=0.64, 95% CI: 0.44, 0.94).ConclusionsThe systematic review of the literature does not support the hypothesis that the use of supplements of vitamin C or vitamin E in the doses tested helps prevent and/or treat cancer in the populations tested. There were isolated findings of benefit, which require confirmation.
Project description:Vitamin D is well known for its function in calcium homeostasis and bone mineralisation, but is increasingly studied for its potential immunomodulatory properties. Vitamin D deficiency is a common problem in patients with COPD. Previous studies have not demonstrated a beneficial effect of vitamin D on exacerbation rate in COPD patients. However, subgroup analyses suggested protective effects in vitamin D deficient patients. Our objective is to assess the effect of vitamin D supplementation on exacerbation rate specifically in vitamin D deficient COPD patients.We will perform a randomised, multi-center, double-blind, placebo-controlled intervention study. The study population consists of 240 COPD patients aged 40 years and older with vitamin D deficiency (25-hydroxyvitamin D concentration?<?50 nmol/L). Participants will be recruited after an exacerbation and will be randomly allocated in a 1:1 ratio to receive vitamin D3 16800 IU or placebo orally once a week during 1 year. Participants will receive a diary card to register the incidence of exacerbations and changes in medication during the study period. Visits will be performed at baseline, at 6 months and at 12 months after randomisation. Participants will undergo spirometry, measurement of total lung capacity and assessment of maximal respiratory mouth pressure. Several physical performance and hand grip strength tests will be performed, questionnaires on quality of life and physical activity will be filled in, a nasal secretion sample and swab will be obtained and blood samples will be taken. The primary outcome will be exacerbation rate.This study will be the first RCT aimed at the effects of vitamin D supplementation on exacerbation rate in vitamin D deficient COPD patients. Also, in contrast to earlier studies that used infrequent dosing regimens, our trial will study effects of a weekly dose of vitamin D supplementation. Secondly, the immunomodulatory effects of vitamin D on host immune response of COPD patients and underlying mechanisms will be studied. Finally, the effects on physical functioning will be examined.This trial is registered in ClinicalTrials.gov, ID number NCT02122627 . Date of Registration April 2014.
Project description:BackgroundVitamin D insufficiency is associated with risks of cardiovascular diseases (CVD) and cancer in observational studies, but evidence for benefits with vitamin D supplementation is limited.ObjectivesTo investigate the effects of vitamin D3 supplementation on CVD and cancer incidences.MethodsThe study was a 5-year, randomized, placebo-controlled trial among 2495 male participants ≥60 years and post-menopausal female participants ≥65 years from a general Finnish population who were free of prior CVD or cancer. The study had 3 arms: placebo, 1600 IU/day, or 3200 IU/day vitamin D3. Follow-up was by annual study questionnaires and national registry data. A representative subcohort of 551 participants had more detailed in-person investigations. The primary endpoints were incident major CVD and invasive cancer. Secondary endpoints included the individual components of the primary CVD endpoint (myocardial infarction, stroke, and CVD mortality), site-specific cancers, and cancer death.ResultsDuring the follow-up, there were 41 (4.9%), 42 (5.0%), and 36 (4.3%) major CVD events in the placebo, 1600 IU/d (compared with placebo: HR: 0.97; 95% CI: 0.63-1.49; P = 0.89), and 3200 IU/d (HR: 0.84; 95% CI: 0.54-1.31; P = 0.44) arms, respectively. Invasive cancer was diagnosed in 41 (4.9%), 48 (5.8%), and 40 (4.8%) participants in the placebo, 1600 IU/d (HR: 1.14; 95% CI: 0.75-1.72; P = 0.55), and 3200 IU/d (HR: 0.95; 95% CI: 0.61-1.47; P = 0.81) arms, respectively. There were no significant differences in the secondary endpoints or total mortality. In the subcohort, the mean baseline serum 25-hydroxyvitamin D concentration was 75 nmol/L (SD, 18 nmol/L). After 12 months, the concentrations were 73 nmol/L (SD, 18 nmol/L), 100 nmol/L (SD, 21 nmol/L), and 120 nmol/L (SD, 22 nmol/L) in the placebo, 1600 IU/d, and 3200 IU/d arms, respectively.ConclusionsVitamin D3 supplementation did not lower the incidences of major CVD events or invasive cancer among older adults, possibly due to sufficient vitamin D status in most participants at baseline.