811 resultados para vitamin A deficiency
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In a previous study, we demonstrated that mouse adult F(1) offspring, exposed to a vitamin d deficiency during pregnancy, developed a less severe and delayed Experimental Autoimmune Encephalomyelitis (EAE), when compared with control offspring. We then wondered whether a similar response was observed in the subsequent generation. To answer this question, we assessed F(2) females whose F(1) parents (males or females) were vitamin d-deprived when developing in the uterus of F(0) females. Unexpectedly, we observed that the vitamin d deficiency affecting the F(0) pregnant mice induced a precocious and more severe EAE in the F(2) generation. This paradoxical finding led us to assess its implications for the epidemiology of Multiple Sclerosis (MS) in humans. Using the REFGENSEP database for MS trios (the patient and his/her parents), we collected the parents' dates of birth and assessed a potential season of birth effect that could potentially be indicative of the vitamin d status of the pregnant grandmothers. A trend for a reduced number of births in the Fall for the parents of MS patients was observed but statistical significance was not reached. Further well powered studies are warranted to validate the latter finding.
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OBJECTIVE There has been a dramatic increase in vitamin D testing in Australia in recent years, prompting calls for targeted testing. We sought to develop a model to identify people most at risk of vitamin D deficiency. DESIGN AND PARTICIPANTS This is a cross-sectional study of 644 60- to 84-year-old participants, 95% of whom were Caucasian, who took part in a pilot randomized controlled trial of vitamin D supplementation. MEASUREMENTS Baseline 25(OH)D was measured using the Diasorin Liaison platform. Vitamin D insufficiency and deficiency were defined using 50 and 25 nmol/l as cut-points, respectively. A questionnaire was used to obtain information on demographic characteristics and lifestyle factors. We used multivariate logistic regression to predict low vitamin D and calculated the net benefit of using the model compared with 'test-all' and 'test-none' strategies. RESULTS The mean serum 25(OH)D was 42 (SD 14) nmol/1. Seventy-five per cent of participants were vitamin D insufficient and 10% deficient. Serum 25(OH)D was positively correlated with time outdoors, physical activity, vitamin D intake and ambient UVR, and inversely correlated with age, BMI and poor self-reported health status. These predictors explained approximately 21% of the variance in serum 25(OH)D. The area under the ROC curve predicting vitamin D deficiency was 0·82. Net benefit for the prediction model was higher than that for the 'test-all' strategy at all probability thresholds and higher than the 'test-none' strategy for probabilities up to 60%. CONCLUSION Our model could predict vitamin D deficiency with reasonable accuracy, but it needs to be validated in other populations before being implemented.
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Results of recent studies suggest that circulating levels of vitamin D may play an important role in cancer-specific outcomes. The present systematic review was undertaken to determine the prevalence of vitamin D deficiency (<25 nmol/L) and insufficiency (25-50 nmol/L) in cancer patients and to evaluate the association between circulating calcidiol (the indicator of vitamin D status) and clinical outcomes. A systematic search of original, peer-reviewed studies on calcidiol at cancer diagnosis, and throughout treatment and survival, was conducted yielding 4,706 studies. A total of 37 studies met the inclusion criteria for this review. Reported mean blood calcidiol levels ranged from 24.7 to 87.4 nmol/L, with up to 31% of patients identified as deficient and 67% as insufficient. The efficacy of cholecalciferol supplementation for raising the concentration of circulating calcidiol is unclear; standard supplement regimens of <1,000 IU D3 /day may not be sufficient to maintain adequate concentrations or prevent decreasing calcidiol. Dose-response studies linking vitamin D status to musculoskeletal and survival outcomes in cancer patients are lacking.
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PURPOSE: This study aims to investigate the prevalence and factors predictive of vitamin D deficiency in patients with malignancy in Brisbane, Australia (latitude 27° S). METHODS: This is a prospective cross-sectional study measuring serum levels of 25-hydroxyvitamin D (25-OHD) in 100 subjects with non-haematological cancer at least 18 years of age not taking vitamin D supplements attending a day oncology unit and oncology/palliative care inpatient ward in Brisbane, Australia. RESULTS: Thirty-seven per cent of outpatient and 49 % of inpatient subjects respectively were vitamin D deficient. Functional status was predictive of low vitamin D levels. CONCLUSION: There was a high prevalence of vitamin D deficiency in patients with cancer in Brisbane, Australia.
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This thesis assesses clinical differences in patients with low and high vitamin D levels. The factors analyzed included the underlying disease, body size, age, ethnic background, use of vitamin D supplements and the season when the blood sample was taken. Fifty patients with the lowest and 50 patients with the highest vitamin D concentrations were selected from a cohort of 1351 chronically ill children and adolescents who had had their vitamin D status assessed at Children's Hospital. Protective factors appeared to be the usage of vitamin D supplements and young age, especially age <2 years. Predisposing factors included non-Finnish ethnic background and older age, especially age 12-18 years. High vitamin D values were more prevalent in the summer and autumn and low values in the winter and spring. Patients with non-Finnish background were overrepresented in the low value group. No differences regarding the underlying diseases could be detected. Conclusions: In the Northern latitudes UVB-radiation is insufficient for vitamin D synthesis. Vitamin D recommendations appear to be inadequate to fulfill the needs of chronically ill patients whose requirements for vitamin D are elevated compared to the general population. New guidelines for vitamin D supplementation are needed particularly for those at risk of developing vitamin D deficiency.
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info:eu-repo/semantics/published
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Allergic asthma is a complex immunologically mediated disease associated with increased oxidative stress and altered antioxidant defenses. It was hypothesized that a-tocopherol (a-T) decreases oxidative stress and therefore its absence may influence allergic inflammatory process, a pathobiology known to be accompanied by oxidative stress. Therefore, selected parameters of allergic asthma sensitization and inflammation were evaluated following ovalbumin sensitization and re-challenge of a-T transfer protein (TTP) knock-out mice (TTP-/-) that have greatly reduced lung a-T levels (e.g.
Homocysteine and methylmalonic acid as indicators of folate and vitamin B12 deficiency in pregnancy.
Resumo:
Maternal vitamin D insufficiency is associated with childhood rickets and longer-term problems including schizophrenia and type 1 diabetes. Whilst maternal vitamin D insufficiency is common in mothers with highly pigmented skin, little is known about vitamin D status of Caucasian pregnant women. The aim was to investigate vitamin D status in healthy Caucasian pregnant women and a group of age-matched non-pregnant controls living at 54–55°N. In a longitudinal study, plasma 25-hydroxyvitamin D (25(OH)D) was assessed in ninety-nine pregnant women at 12, 20 and 35 weeks of gestation, and in thirty-eight non-pregnant women sampled concurrently. Plasma 25(OH)D concentrations were lower in pregnant women compared to non-pregnant women (P < 0·0001). Of the pregnant women, 35, 44 and 16 % were classified as vitamin D deficient (25(OH)D < 25 nmol/l), and 96, 96 and 75 % were classified as vitamin D insufficient (25(OH)D < 50 nmol/l) at 12, 20 and 35 weeks gestation, respectively. Vitamin D status was higher in pregnant women who reported taking multivitamin supplements at 12 (P < 0·0001), 20 (P = 0·001) and 35 (P = 0·001) weeks gestation than in non-supplement users. Vitamin D insufficiency is evident in pregnant women living at 54–55°N. Women reporting use of vitamin D-containing supplements had higher vitamin D status, however, vitamin D insufficiency was still evident even in the face of supplement use. Given the potential consequences of hypovitaminosis D on health outcomes, vitamin D supplementation, perhaps at higher doses than currently available, is needed to improve maternal vitamin D nutriture.
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Disertação de mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2015