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    ABSTRACT: The relationship between serum vitamin D levels and atopy is an up to date topic. Most studies, particularly transversal and observational studies, demonstrate that there is a relationship between vitamin D deficiency and symptoms of atopy (rhinitis, asthma, atopic dermatitis, food allergies). Vitamin D deficiency is more frequently observed in atopic children than in controls in the general population. Vitamin D could play a major role in the genesis of allergies because of its multiple extra- osseous effects, particularly on natural and acquired immunity. Variations in exposure to UV- B radiation leading to differences in vitamin D synthesis could explain the North- South gradient described in epidemiological studies for most symptoms of atopy. The same theory could explain the significant excess in food allergies observed in children born during the cold season in both hemispheres. In some studies, prescription of vitamin D to patients with deficiencies improved their symptoms, i.e. better control of asthma, improvement in atopic dermatitis scores. The demonstration that the vitamin D status of pregnant women has an effect on the later development of allergic or infectious diseases (bronchiolitis, tuberculosis) in their children further accentuated the importance of the relationship between vitamin D, atopy and immunity. Large, prospective studies are currently underway to define the precise nature of this relationship and its practical clinical impact.
    Revue Française d'Allergologie 10/2012; 52:S10–S18. DOI:10.1016/S1877-0320(12)70038-6 · 0.35 Impact Factor
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    ABSTRACT: Aboriginal peoples affected by a nutrition transition and living at high latitudes are among the ethnic groups most at risk of vitamin D deficiency. The objectives of this study were to determine the prevalence of meeting predefined cut-off concentrations of vitamin D and to examine associated factors among James Bay Cree aged ³15 years. A cross-sectional study was conducted between the months of May and September from 2005 to 2009. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by radioimmunoassay. Anthropometrics were measured and additional information on socio-demographic characteristics, lifestyle and dietary habits was obtained using questionnaires. A logistic regression model predicting vitamin D insufficiency (<50 nmol/L) included known covariates. Data were obtained from 944 Cree (406 men (43%); mean age 37.4 years), with an effective participation rate of 49% among women and 41% among men. Mean serum 25(OH)D concentrations (nmol/L) by gender were 52.9 (95% CI 51.4-54.5) in men and 47.5 (95% CI 46.2-48.9) in women, and by age group were 46.0 (95% CI 44.9-48.9) in those 15-39 years and 59.6 (95% CI 57.9-61.4) in those ³40 years of age. Overall, 5.8%, 42.6%, 40.0%, and 11.7% of the participants had 25(OH)D concentrations <30, 30-49.9, 50-74.9 and ³75 nmol/L, respectively. Female gender, obesity, younger age, spring, low fish and milk intake, and low vigorous physical activity predicted vitamin D insufficiency (all p<0.05). The vitamin D status in Eastern James Bay Cree is suboptimal with nearly half of the population having insufficient concentrations for optimum bone health.
    01/2013; 104(4):e291-7.
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    ABSTRACT: Vitamin D is a key nutrient for both healthy children and those with chronic illnesses. Understanding its roles in health and disease has become one of the most important issues in the nutritional management of children. Formal guidelines related to nutrient requirements for vitamin D in healthy children, recommending dietary intakes of 400 IU per day for infants and 600 IU per day for children over 1 year of age, were released by the Institute of Medicine in November 2010. However, application of these guidelines to children with acute and chronic illnesses is less clear. In this Review, we consider major illness categories and specific examples of conditions in children that might be affected by vitamin D. This information can be used in developing both model systems of investigation and clinical trials of vitamin D in children with acute and chronic illnesses.
    Nature Reviews Endocrinology 02/2013; 9(3). DOI:10.1038/nrendo.2012.259 · 12.96 Impact Factor
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