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Objective: To examine the associations between serum 25-hydroxyvitamin D (25(OH)D) levels and serum liver enzymes in a representative sample of US adults.Design: The cross-sectional study sample consisted of 24 229 adults with data on serum 25(OH)D levels and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transaminase (GGT) concentrations, in addition to data on other potential confounders. Multivariate logistic regression and linear regression were applied to assess the associations between serum 25(OH)D levels and ALT, AST, ALP and GGT concentrations.Setting: The National Health and Nutrition Examination Survey, 2001-2006.Participants: The cross-sectional study sample consisted of 24 229 adults.Results: We found a significant association between low serum 25(OH)D levels (<30 nmol/l) and ALP levels in all participants (OR 2·67; 95 % CI 1·98, 3·59; P < 0·001), a confirmed healthy population (OR 3·02; 95 % CI 2·25, 4·07; P < 0·001) and individuals with viral hepatitis (OR 2·87; 95 % CI 1·52, 5·44; P = 0·006) compared with those who had normal 25(OH)D levels (>50 nmol/l). Moreover, in both the logistic regression and linear regression, the associations between 25(OH)D levels and ALP levels were stronger in the subgroups with obesity. No association was present between ALT, AST or GGT levels and serum 25(OH)D levels in this population.Conclusions: The results of the present study provide epidemiological evidence that vitamin D deficiency is associated with liver ALP levels in humans. This finding suggests a potential adverse effect of low 25(OH)D levels on human liver function. However, the underlying mechanisms still need further investigation. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether vitamin D status predicts weight gain or increase in waist circumference during the 11-year follow-up in general adult population.Design: A population-based longitudinal study.Setting: The study was conducted using data from the nationally representative Health 2000/2011 Survey. The analyses were based on regression models adjusted for sociodemographic and lifestyle factors.Participants: Weight, waist circumference and vitamin D status (serum 25-hydroxyvitamin D concentration analysed with radioimmunoassay) were measured from 2924 participants aged 30-64 years at baseline.Results: In men, low vitamin D status at baseline predicted ≥10 % increase in waist circumference during the follow-up when adjusted for age only (OR for sufficient v. deficient S-25(OH)D 0·41; 95 % CI 0·25, 0·67; P for trend <0·01), but the association with weight gain was only borderline significant. After adjustment for potential confounders, low vitamin D status remained a significant predictor of increase in waist circumference, but the association with weight gain was further attenuated. In women, vitamin D status at baseline did not predict weight gain or increase in waist circumference.Conclusions: Our results suggest that vitamin D insufficiency may be a risk factor of abdominal obesity among men but not among women. In men, it may also increase the risk of weight gain. Further studies are required to confirm these findings and examine potential mechanisms behind them. There is also a possibility that vitamin D is a biomarker of healthy lifestyle rather than an independent risk factor for obesity. [ABSTRACT FROM AUTHOR]

Objective: To examine the hypothesis that the association between vitamin D deficiency and depressive symptoms is dependent upon total cholesterol level in a representative national sample of the South Korean population.Design: This was a population-based cross-sectional study.Setting: The Fifth Korean National Health and Nutrition Examination Survey (KNHANES V, 2010-2012).Subjects: We included 7198 adults aged 20-88 years.Results: The incidence of depressive symptoms in individuals with vitamin D deficiency (serum 25-hydroxyvitamin D<20 ng/ml) was 1·54-fold (95 % CI 1·20, 1·98) greater than in individuals without vitamin D deficiency (serum 25-hydroxyvitamin D ≥20 ng/ml). The relationship was stronger in individuals with normal-to-borderline serum total cholesterol (serum total cholesterol<240 mg/dl; OR=1·60; 95 % CI 1·23, 2·08) and non-significant in individuals with high serum total cholesterol (OR=0·97; 95 % CI 0·52, 1·81) after adjustment for confounding variables (age, sex, BMI, alcohol consumption, smoking status, regular exercise, income level, education level, marital status, changes in body weight, perceived body shape, season of examination date and cholesterol profiles).Conclusions: The association between vitamin D deficiency and depressive symptoms was weakened by high serum total cholesterol status. These findings suggest that both vitamin D and total cholesterol are important targets for the prevention and treatment of depression. [ABSTRACT FROM AUTHOR]

Objective: Poor nutrition and limited sunlight exposure (season) can be related to reduced serum 25-hydroxyvitamin D (25(OH)D) concentrations. Thus, elderly people in the Nordic countries might be at high risk for vitamin D deficiency. The aims of the study were to describe the prevalence of vitamin D deficiency in elderly hospitalized patients in Reykjavik, Iceland, and to investigate the effects of nutritional status and season on serum 25(OH)D. Design: Cross-sectional study. Nutritional status was assessed and fasting blood was drawn and analysed for serum 25(OH)D and other clinical routine measurements. Setting: Departments of Geriatrics, Landspitali-University Hospital, Reykjavik, Iceland. Subjects: Sixty hospitalized patients (mean age 83·0 (SD 7·9) years) were randomly assigned. Results: Of the patients, 12·3% suffered from vitamin D deficiency (serum 25(OH)D,25 nmol/l) and 71·9% suffered from hypovitaminosis D (serum 25(OH)D525-75 nmol/l). There were no significant effects of gender or nutritional status on serum 25(OH)D. Anthropometric variables correlated significantly with serum 25(OH)D, but on stepwise linear regression modelling for the prediction of serum 25(OH)D, BMI remained the only predictor variable (B=21·454, 95% CI 22·535, 20·373, P=0·009). Conclusions: BMI was significantly negatively associated with serum 25(OH)D in hospitalized elderly patients. Neither nutritional status nor season significantly affected serum 25(OH)D in our patient group. Higher levels of serum 25(OH)D in elderly subjects with lower BMI are most likely explained by volume of distribution rather than by mobilization of vitamin D from its storage in adipose tissue due to age and disease-related catabolism. [ABSTRACT FROM AUTHOR]

Objective: To examine the hypothesis that the association between vitamin D deficiency and depressive symptoms is dependent upon total cholesterol level in a representative national sample of the South Korean population., Design: This was a population-based cross-sectional study., Setting: The Fifth Korean National Health and Nutrition Examination Survey (KNHANES V, 2010-2012)., Subjects: We included 7198 adults aged 20-88 years., Results: The incidence of depressive symptoms in individuals with vitamin D deficiency (serum 25-hydroxyvitamin D<20 ng/ml) was 1·54-fold (95 % CI 1·20, 1·98) greater than in individuals without vitamin D deficiency (serum 25-hydroxyvitamin D ≥20 ng/ml). The relationship was stronger in individuals with normal-to-borderline serum total cholesterol (serum total cholesterol<240 mg/dl; OR=1·60; 95 % CI 1·23, 2·08) and non-significant in individuals with high serum total cholesterol (OR=0·97; 95 % CI 0·52, 1·81) after adjustment for confounding variables (age, sex, BMI, alcohol consumption, smoking status, regular exercise, income level, education level, marital status, changes in body weight, perceived body shape, season of examination date and cholesterol profiles)., Conclusions: The association between vitamin D deficiency and depressive symptoms was weakened by high serum total cholesterol status. These findings suggest that both vitamin D and total cholesterol are important targets for the prevention and treatment of depression.