Vitamin D status and its predictors among pre-school children in Adelaide.

AIM: To assess vitamin D status and its predictors in a representative population sample of pre-school children in Adelaide (latitude of 35°S). METHODS: Cross-sectional survey of children aged between 1 and 5 years from areas of low, medium and high socio-economic status as identified from the 2001 Census data, Australian Bureau of Statistics. Children were recruited between September 2005 and July 2007 using a door knocking protocol based on a stratified sampling method to obtain a representative sample of this age group. Serum 25-hydroxyvitamin D (25(OH)D) was determined using a radio-immunoassay kit. Vitamin D deficiency was defined as serum 25(OH)D) <30 nmol/L and insufficiency defined as serum 25(OH)D ≥30 and <50 nmol/L according to the Institute of Medicine. RESULTS: Fifty-two per cent of eligible children took part in the study. Mean (standard deviation) serum 25(OH)D was 73 (26) nmol/L (n = 221). The prevalence of vitamin D deficiency and insufficiency was 4% and 16%, respectively, with the prevalence being higher in winter (8% and 22%, respectively). Season of the year of blood collection and mother being born in Australia were significant predictors of serum 25(OH)D concentration, but age, sex, socio-economic status, BMI category or dietary supplement use were not related to vitamin D status. CONCLUSIONS: Vitamin D status of this representative sample of pre-school children in Australia is adequate, and the prevalence of vitamin D deficiency is low based on the Institute of Medicine criteria.

Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals.

BACKGROUND: Elevated plasma homocysteine is a risk factor for Alzheimer disease, but the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain. OBJECTIVE: The aim was to assess the effects of treatment with B vitamins compared with placebo, when administered for several years, on composite domains of cognitive function, global cognitive function, and cognitive aging. DESIGN: A meta-analysis was conducted by using data combined from 11 large trials in 22,000 participants. Domain-based z scores (for memory, speed, and executive function and a domain-composite score for global cognitive function) were available before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE)-type tests were available at the end of treatment (mean duration: 5 y) in the 7 global cognition trials (20,431 individuals). RESULTS: The domain-composite and MMSE-type global cognitive function z scores both decreased with age (mean ± SE: -0.054 ± 0.004 and -0.036 ± 0.001/y, respectively). Allocation to B vitamins lowered homocysteine concentrations by 28% in the cognitive-domain trials but had no significant effects on the z score differences from baseline for individual domains or for global cognitive function (z score difference: 0.00; 95% CI: -0.05, 0.06). Likewise, allocation to B vitamins lowered homocysteine by 26% in the global cognition trials but also had no significant effect on end-treatment MMSE-type global cognitive function (z score difference: -0.01; 95% CI: -0.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: -0.10, 0.13 y) of cognitive aging per year and excluded reductions of >1 mo per year of treatment. CONCLUSION: Homocysteine lowering by using B vitamins had no significant effect on individual cognitive domains or global cognitive function or on cognitive aging.

Changes in markers of inflammation, antioxidant capacity and oxidative stress in smokers following consumption of milk, and milk supplemented with fruit and vegetable extracts and vitamin C.

Two milk-based beverages delivering twice the average daily antioxidant intake were formulated, based on synergistic combinations of fruit and vegetable extracts, and containing vitamin C (1.00 mg/ml) for shelf stability. Smokers (n = 42) consumed prototype milk A, B or non-supplemented milk (no extracts or vitamin C; 200 ml) twice daily for 6 weeks. Fasting and post-prandial (2 h after milk consumption) blood samples were collected at baseline and the end of each treatment. Non-supplemented milk significantly reduced fasting inflammatory cytokines (interleukin (IL) 6, IL-1ß, tumour necrosis factor-α) compared to baseline. Both supplemented milk-based beverages significantly increased fasting plasma vitamin C concentrations and antioxidant potential and decreased serum uric acid, compared to non-supplemented milk. The beverages did not induce post-prandial oxidative stress or inflammation. Therefore, regular consumption of the supplemented milks may confer health benefits because of increased antioxidant potential or through mechanisms resulting from increased vitamin C or decreased uric acid concentrations.