scholarly journals Vitamin D: emerging new roles in insulin sensitivity

2009 ◽  
Vol 22 (1) ◽  
pp. 82-92 ◽  
Author(s):  
Dorothy Teegarden ◽  
Shawn S. Donkin
Keyword(s):  
Vitamin D ◽  
Insulin Sensitivity ◽  
Clinical Intervention ◽  
Epidemiological Studies ◽  
Receptor Expression ◽  
Vitamin D Status ◽  
Hydroxyvitamin D ◽  
Normal Ranges ◽  
Underlying Mechanisms ◽  
Insulin Receptor Expression

The growing incidence of prediabetes and clinical type 2 diabetes, in part characterised by insulin resistance, is a critical health problem with consequent devastating personal and health-care costs. Vitamin D status, assessed by serum 25-hydroxyvitamin D levels, is inversely associated with diabetes in epidemiological studies. Several clinical intervention studies also support that vitamin D, or its active metabolite 1,25-dihydroxyvitamin D (1,25(OH)2D), improves insulin sensitivity, even in subjects with glucose metabolism parameters classified within normal ranges. The mechanisms proposed which may underlie this effect include potential relationships with improvements in lean mass, regulation of insulin release, altered insulin receptor expression and specific effects on insulin action. These actions may be mediated by systemic or local production of 1,25(OH)2D or by suppression of parathyroid hormone, which may function to negatively affect insulin sensitivity. Thus, substantial evidence supports a relationship between vitamin D status and insulin sensitivity; however, the underlying mechanisms require further exploration.

scholarly journals Determinants of plasma 25-hydroxyvitamin D and development of prediction models in three US cohorts

2012 ◽  
Vol 108 (10) ◽  
pp. 1889-1896 ◽  
Author(s):  
Kimberly A. Bertrand ◽  
Edward Giovannucci ◽  
Yan Liu ◽  
Susan Malspeis ◽  
A. Heather Eliassen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Prediction Models ◽  
Epidemiological Studies ◽  
Health Study ◽  
Control Analysis ◽  
Vitamin D Status ◽  
Blood Draw ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Hormone Use

Epidemiological and other evidence suggests that vitamin D may be protective against several chronic diseases. Assessing vitamin D status in epidemiological studies, however, is challenging given finite resources and limitations of commonly used approaches. Using multivariable linear regression, we derived predicted 25-hydroxyvitamin D (25(OH)D) scores based on known determinants of circulating 25(OH)D, including age, race, UV-B radiation flux at residence, dietary and supplementary vitamin D intakes, BMI, physical activity, alcohol intake, post-menopausal hormone use (women only) and season of blood draw, in three nationwide cohorts: the Nurses' Health Study, Nurses' Health Study II and the Health Professionals Follow-up Study. The model r2 for each cohort ranged from 0·25 to 0·33. We validated the prediction models in independent samples of participants from these studies. Mean measured 25(OH)D levels rose with increasing decile of predicted 25(OH)D score, such that the differences in mean measured 25(OH)D between the extreme deciles of predicted 25(OH)D were in the range 8·7–12·3 ng/ml. Substituting predicted 25(OH)D scores for measured 25(OH)D in a previously published case–control analysis of colorectal cancer yielded similar effect estimates with OR of approximately 0·8 for a 10 ng/ml difference in either plasma or predicted 25(OH)D. We conclude that these data provide reasonable evidence that a predicted 25(OH)D score is an acceptable marker for ranking individuals by long-term vitamin D status and may be particularly useful in research settings where biomarkers are not available for the majority of a study population.

scholarly journals Calcium and vitamin D in obesity

2012 ◽  
Vol 25 (1) ◽  
pp. 130-141 ◽  
Author(s):  
Qingming Song ◽  
Igor N. Sergeev
Keyword(s):  
Vitamin D ◽  
Clinical Intervention ◽  
Epidemiological Studies ◽  
Vitamin D Status ◽  
Negative State ◽  
Increased Risk ◽  
Research Findings ◽  
Intervention Trials ◽  
Fat Excretion

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.

scholarly journals Comparison of Vitamin D and 25-Hydroxyvitamin D Concentrations in Human Breast Milk between 1989 and 2016–2017

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 573
Author(s):  
Naoko Tsugawa ◽  
Mayu Nishino ◽  
Akiko Kuwabara ◽  
Honami Ogasawara ◽  
Maya Kamao ◽  
...  
Keyword(s):  
Vitamin D ◽  
Breast Milk ◽  
Sun Exposure ◽  
Stepwise Multiple Regression ◽  
Human Breast Milk ◽  
Vitamin D Status ◽  
Human Breast ◽  
Hydroxyvitamin D ◽  
Lactating Mothers ◽  
25 Hydroxyvitamin D

Background: Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016–2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016–2017) and vitamin D status in human breast milk was also evaluated. Method: Lactating mothers were recruited from three regions of Japan in 1989 (n = 72) and 2016–2017 (n = 90), and milk from 3–4 months was collected in summer and winter. The samples were strictly sealed and stored at −80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016–2017 were assessed. Results: Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016–2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D3 concentrations. Conclusion: The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.

scholarly journals Implementation Strategies for Improving Vitamin D Status and Increasing Vitamin D Intake in the UK: Current Controversies and Future Perspectives. Proceedings of the 2nd Rank Prize Funds Forum on Vitamin D

2021 ◽  
pp. 1-60
Author(s):  
J.L. Buttriss ◽  
S.A. Lanham-New ◽  
S. Steenson ◽  
L. Levy ◽  
G.E. Swan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Age Groups ◽  
Implementation Strategies ◽  
Vitamin D Status ◽  
Cost Information ◽  
Hydroxyvitamin D ◽  
Minority Ethnic Groups ◽  
Modelling Studies ◽  
Clinical Consequences ◽  
The Uk

Abstract A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK, and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a RNI (10µg/day;400IU/day) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups, and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. It is too early to establish whether population vitamin D status has altered since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens’ eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: i) need for ‘real-world’ cost information for use in modelling work; ii) supportive food legislation; iii) improved consumer and health professional understanding of vitamin D’s importance; iv) clinical consequences of inadequate vitamin D status; v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

scholarly journals COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1714
Author(s):  
Habiba AlSafar ◽  
William B. Grant ◽  
Rafiq Hijazi ◽  
Maimunah Uddin ◽  
Nawal Alkaabi ◽  
...  
Keyword(s):  
Vitamin D ◽  
United Arab Emirates ◽  
Blood Levels ◽  
Vitamin D Status ◽  
Hospital Visit ◽  
Serum Samples ◽  
Hydroxyvitamin D ◽  
Increased Risk ◽  
Multiethnic Population ◽  
25 Hydroxyvitamin D

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.

scholarly journals Vitamin D Status and Seasonal Variation among Danish Children and Adults: A Descriptive Study

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1801 ◽  
Author(s):  
Louise Hansen ◽  
Anne Tjønneland ◽  
Brian Køster ◽  
Christine Brot ◽  
Rikke Andersen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Seasonal Variation ◽  
Vitamin D Status ◽  
Hydroxyvitamin D ◽  
Supplement Use ◽  
Wide Range ◽  
Adults And Children ◽  
25 Hydroxyvitamin D ◽  
Vitamin D Supplement ◽  
Very High

The aim of the present study was to describe vitamin D status and seasonal variation in the general Danish population. In this study, 3092 persons aged 2 to 69 years (2565 adults, 527 children) had blood drawn twice (spring and autumn) between 2012 and 2014. A sub-sample of participants had blood samples taken monthly over a year. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by liquid chromatography mass spectrometry, and information on supplement use was assessed from questionnaires. Seasonal variations in 25(OH)D concentrations were evaluated graphically and descriptively, and status according to age, sex, and supplement use was described. It was found that 86% of both adults and children were vitamin D-sufficient in either spring and or/autumn; however, many had a spring concentration below 50 nmol/L. A wide range of 25(OH)D concentrations were found in spring and autumn, with very low and very high values in both seasons. Among adults, women in general had higher median 25(OH)D concentrations than men. Furthermore, vitamin D supplement use was substantial and affected the median concentrations markedly, more so during spring than autumn. Seasonal variation was thus found to be substantial, and bi-seasonal measurements are vital in order to capture the sizable fluctuations in vitamin D status in this Nordic population.

scholarly journals Weight and skin colour as predictors of vitamin D status: results of an epidemiological investigation using nationally representative data

2016 ◽  
Vol 20 (10) ◽  
pp. 1857-1864 ◽  
Author(s):  
Sonali Rajan ◽  
Tom Weishaar ◽  
Bryan Keller
Keyword(s):  
Vitamin D ◽  
Body Weight ◽  
Skin Colour ◽  
Vitamin D Status ◽  
Epidemiological Investigation ◽  
Dietary Recommendations ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Nationally Representative ◽  
The Impact

AbstractObjectiveCurrent US dietary recommendations for vitamin D vary by age. Recent research suggests that body weight and skin colour are also major determinants of vitamin D status. The objective of the present epidemiological investigation was to clarify the role of age as a predictor of vitamin D status, while accounting for body weight and skin colour, among a nationally representative sample.DesignWe calculated the mean serum 25-hydroxyvitamin D levels for the US population by age and weight, as well as by weight and race/ethnicity group. Multiple regression analyses were utilized to evaluate age and weight as predictors of vitamin D status: serum 25-hydroxyvitamin D levels with age alone, age and body weight, and age, body weight and their two-way interaction were modelled for the entire sample and each age subgroup. Graphical data were developed using B-spline non-linear regression.SettingNational Health and Nutrition Examination Survey (31 934 unweighted cases).SubjectsIndividuals aged 1 year and older.ResultsThere were highly significant differences in mean vitamin D status among US residents by weight and skin colour, with those having darker skin colour or higher body weight having worse vitamin D status. Although a significant factor, the impact of age on vitamin D status was notably less than the impact of body weight.ConclusionsVitamin D status varied predominantly by body weight and skin colour. Recommendations by nutritionists for diet and supplementation needs should take this into account if vitamin D-related health disparities are to be meaningfully reduced across the USA.

scholarly journals Vitamin D Status and Severe COVID-19 Disease Outcomes in Hospitalized Patients

2021 ◽  
Vol 12 ◽  
pp. 215013272110412
Author(s):  
Jennifer L. Pecina ◽  
Stephen P. Merry ◽  
John G. Park ◽  
Tom D. Thacher
Keyword(s):  
Vitamin D ◽  
Assisted Ventilation ◽  
Vitamin D Supplementation ◽  
Hospitalized Patients ◽  
Vitamin D Status ◽  
Icu Admission ◽  
Hydroxyvitamin D ◽  
Duration Of Hospitalization ◽  
D Values ◽  
Relationship Of

Background: Vitamin D deficiency may increase the risk of severe COVID-19 disease. Objectives: To determine if 25-hydroxyvitamin D [25(OH)D] levels in patients hospitalized for COVID-19 were associated with the clinical outcomes of days on oxygen, duration of hospitalization, ICU admission, need for assisted ventilation, or mortality. Methods: We conducted a retrospective study of 92 patients admitted to the hospital with SARS-CoV-2 infection between April 16, 2020 and October 17, 2020. Multivariable regression was performed to assess the independent relationship of 25(OH)D values on outcomes, adjusting for significant covariates and the hospitalization day the level was tested. Results: About 15 patients (16.3%) had 25(OH)D levels <20 ng/mL. Only 1 patient (3.4%) who had documented vitamin D supplementation prior to admission had 25(OH)D <20 ng/mL. Serum 25(OH)D concentrations were not significantly associated with any of our primary outcomes of days on oxygen, duration of hospitalization, intensive care unit (ICU) admission, need for mechanical ventilation, or mortality in any of the adjusted multivariable models. Adjusting for the hospital day of 25(OH)D sampling did not alter the relationship of 25(OH)D with any outcomes. Conclusion: Vitamin D status was not related to any of the primary outcomes reflecting severity of COVID-19 in hospitalized patients. However, our sample size may have lacked sufficient power to demonstrate a small effect of vitamin D status on these outcomes.

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