Serum 25-hydroxyvitamin D concentrations and cardiometabolic risk factors in adolescents and young adults.

Evidence associating serum 25-hydroxyvitamin D (25(OH)D) concentrations and cardiometabolic risk factors is inconsistent and studies have largely been conducted in adult populations. We examined the prospective associations between serum 25(OH)D concentrations and cardiometabolic risk factors from adolescence to young adulthood in the West Australian Pregnancy Cohort (Raine) Study. Serum 25(OH)D concentrations, BMI, homoeostasis model assessment for insulin resistance (HOMA-IR), TAG, HDL-cholesterol and systolic blood pressure (SBP) were measured at the 17-year (n 1015) and 20-year (n 1117) follow-ups. Hierarchical linear mixed models with maximum likelihood estimation were used to investigate associations between serum 25(OH)D concentrations and cardiometabolic risk factors, accounting for potential confounders. In males and females, respectively, mean serum 25(OH)D concentrations were 73·6 (sd 28·2) and 75·4 (sd 25·9) nmol/l at 17 years and 70·0 (sd 24·2) and 74·3 (sd 26·2) nmol/l at 20 years. Deseasonalised serum 25(OH)D3 concentrations were inversely associated with BMI (coefficient -0·01; 95 % CI -0·03, -0·003; P=0·014). No change over time was detected in the association for males; for females, the inverse association was stronger at 20 years compared with 17 years. Serum 25(OH)D concentrations were inversely associated with log-HOMA-IR (coefficient -0·002; 95 % CI -0·003, -0·001; P<0·001) and positively associated with log-TAG in females (coefficient 0·002; 95 % CI 0·0008, 0·004; P=0·003). These associations did not vary over time. There were no significant associations between serum 25(OH)D concentrations and HDL-cholesterol or SBP. Clinical trials in those with insufficient vitamin D status may be warranted to determine any beneficial effect of vitamin D supplementation on insulin resistance, while monitoring for any deleterious effect on TAG.

Low serum 25-hydroxyvitamin D concentrations associate with non-alcoholic fatty liver disease in adolescents independent of adiposity.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and serum 25-hydroxyvitamin D (s25[OH]D) concentrations are both associated with adiposity and insulin resistance (IR) and thus may be pathogenically linked. We aimed to determine the prevalence of vitamin D deficiency in adolescents with NAFLD and to investigate the prospective and cross-sectional associations between s25[OH]D concentrations and NAFLD. METHODS: Participants in the population-based West Australian Pregnancy (Raine) Cohort had seasonally adjusted s25(OH)D concentrations determined at ages 14 and then 17 years. NAFLD was diagnosed at 17 years using liver ultrasonography. Associations were examined after adjusting for potential confounders. Odds ratios (ORs) and confidence intervals (CIs) are reported per standard deviation in s25(OH)D concentrations. RESULTS: NAFLD was present in 16% (156/994) of adolescents. The majority of participants with NAFLD had either insufficient (51%) or deficient (17%) vitamin D status. s25(OH)D concentrations at 17 years were inversely associated with risk of NAFLD (OR 0.74, 95% CI 0.56, 0.97; P = 0.029), after adjusting for sex, race, physical activity, television/computer viewing, body mass index, and IR. The effect of s25(OH)D concentrations at 17 years was minimally affected after further adjusting for s25(OH)D concentrations at 14 years (OR 0.76, 95% CI 0.56, 1.03; P = 0.072). CONCLUSIONS: Lower s25(OH)D concentrations are significantly associated with NAFLD, independent of adiposity and IR. Screening for vitamin D deficiency in adolescents at risk of NAFLD is appropriate, and clinical trials investigating the effect of vitamin D supplementation in the prevention and treatment of NAFLD may be warranted.

Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development.

OBJECTIVES: To determine the association between maternal serum 25(OH)-vitamin D concentrations during a critical window of fetal neurodevelopment and behavioral, emotional, and language outcomes of offspring. METHODS: Serum 25(OH)-vitamin D concentrations of 743 Caucasian women in Perth, Western Australia (32°S) were measured at 18 weeks pregnancy and grouped into quartiles. Offspring behavior was measured with the Child Behavior Checklist at 2, 5, 8, 10, 14, and 17 years of age (n range = 412-652). Receptive language was assessed with the Peabody Picture Vocabulary Test-Revised at ages 5 (n = 534) and 10 (n = 474) years. Raw scores were converted to standardized scores, incorporating cutoffs for clinically significant levels of difficulty. RESULTS: χ(2) analyses revealed no significant associations between maternal 25(OH)-vitamin D serum quartiles and offspring behavioral/emotional problems at any age. In contrast, there were significant linear trends between quartiles of maternal vitamin D levels and language impairment at 5 and 10 years of age. Multivariate regression analyses, incorporating a range of confounding variables, found that the risk of women with vitamin D insufficiency (≤46 nmol/L) during pregnancy having a child with clinically significant language difficulties was increased close to twofold compared with women with vitamin D levels >70 nmol/L. CONCLUSIONS: Maternal vitamin D insufficiency during pregnancy is significantly associated with offspring language impairment. Maternal vitamin D supplementation during pregnancy may reduce the risk of developmental language difficulties among their children.

Fish oil supplementation in pregnancy modifies neonatal progenitors at birth in infants at risk of atopy.

Dietary n-3 polyunsaturated fatty acids (PUFA) may represent a mode of allergy prevention. Cord blood (CB) CD34+ hemopoietic progenitors are altered in infants at risk of atopy. We therefore studied the effects of dietary n-3 PUFA supplementation during pregnancy on numbers and function of progenitors in neonates at high risk of atopy. In a double-blind study, atopic, pregnant women were randomized to receive fish oil capsules or placebo from 20 wk gestation until delivery. At birth, CB CD34+ cells were isolated and analyzed by flow cytometry for expression of cytokine (IL-5Ralpha, IL-3Ralpha, granulocyte/macrophage colony-stimulating factor Ralpha) or chemokine (CXCR4 and CCR3) receptors. CB cells were also cultured in methylcellulose assays for eosinophil/basophil colony-forming cells. At age 1 y, infants were clinically assessed for atopic symptoms and skin tests. Percentages of CB CD34+ cell numbers were higher after n-3 PUFA than placebo. Co-expression of cytokine or chemokine receptors on CD34 cells was not altered by n-3 PUFA supplementation. However, there were significantly more IL-5-responsive CB eosinophil/basophil colony forming units (Eo/B-CFU) in the fish oil, compared with the control, group. Overall, there was a positive association between CD34+ cells and IL-5-responsive Eo/B-CFU in CB and 1 y clinical outcomes, including atopic dermatitis and wheeze. Dietary n-3 PUFA supplementation during pregnancy in atopic mothers alters infant cord blood hemopoietic progenitor phenotype. This may have an impact on development of atopic disease.

Fish oil supplementation in pregnancy modifies neonatal allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial.

BACKGROUND: There is growing interest in the potential role of anti-inflammatory n-3 polyunsaturated fatty acids (n-3 PUFAs) in the prevention of allergic disease. OBJECTIVE: We sought to determine whether maternal dietary supplementation with n-3 PUFAs during pregnancy could modify immune responses in infants. METHODS: In a randomized, controlled trial 98 atopic, pregnant women received fish oil (3.7 g n-3 PUFAs per day) or placebo from 20 weeks' gestation until delivery. Neonatal PUFA levels and immunologic response to allergens were measured at birth. RESULTS: Eighty-three women completed the study. Fish oil supplementation (n = 40) achieved significantly higher proportions of n-3 PUFAs in neonatal erythrocyte membranes (mean +/- SD, 17.75% +/- 1.85% as a percentage of total fatty acids) compared with the control group (n = 43, 13.69% +/- 1.22%, P <.001). All neonatal cytokine (IL-5, IL-13, IL-10, and IFN-gamma) responses (to all allergens) tended to be lower in the fish oil group (statistically significant only for IL-10 in response to cat). Although this study was not designed to examine clinical effects, we noted that infants in the fish oil group were 3 times less likely to have a positive skin prick test to egg at 1 year of age (odds ratio, 0.34; 95% confidence interval, 0.11 to 1.02; P =.055). Although there was no difference in the frequency of atopic dermatitis at 1 year of age, infants in the fish oil group also had significantly less severe disease (odds ratio, 0.09; 95% confidence interval, 0.01 to 0.94; P =.045). CONCLUSIONS: These data suggest a potential reduction in subsequent infant allergy after maternal PUFA supplementation. More detailed follow-up studies are required in larger cohorts to establish the robustness of these findings and to ascertain their significance in relation to longer-term modification of allergic disease in children.