Appropriateness of the probability approach with a nutrient status biomarker to assess population inadequacy: a study using vitamin D

Background: There are questions about the appropriate method for the accurate estimation of the population prevalence of nutrient inadequacy on the basis of a biomarker of nutrient status (BNS). Objective: We determined the applicability of a statistical probability method to a BNS, specifically serum 25-hydroxyvitamin D [25(OH)D]. The ability to meet required statistical assumptions was the central focus. Design: Data on serum 25(OH)D concentrations in adults aged 19–70 y from the 2005–2006 NHANES were used (n = 3871). An Institute of Medicine report provided reference values. We analyzed key assumptions of symmetry, differences in variance, and the independence of distributions. We also corrected observed distributions for within-person variability (WPV). Estimates of vitamin D inadequacy were determined. Results:We showed that the BNS [serum 25(OH)D] met the criteria to use the method for the estimation of the prevalence of inadequacy. The difference between observations corrected compared with uncorrected for WPV was small for serum 25(OH)D but, nonetheless, showed enhanced accuracy because of correction. The method estimated a 19% prevalence of inadequacy in this sample, whereas misclassification inherent in the use of the more traditional 97.5th percentile high-end cutoff inflated the prevalence of inadequacy (36%). Conclusions: When the prevalence of nutrient inadequacy for a population is estimated by using serum 25(OH)D as an example of a BNS, a statistical probability method is appropriate and more accurate in comparison with a high-end cutoff. Contrary to a common misunderstanding, the method does not overlook segments of the population. The accuracy of population estimates of inadequacy is enhanced by the correction of observed measures for WPV

Organized Activity Participation, Positive Youth Development, and the Over‐Scheduling Hypothesis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145279/1/sop200049.pd

Proprietary Considerations

Background: Celiac disease (CD) and type 1 diabetes (T1D) are two chronic autoimmune diseases with increasing incidence worldwide. A combination of genetic, environmental and immunological factors is considered to be involved in development of the diseases, even though the exact disease mechanisms still are unknown. CD and T1D are both believed to be associated with type 1 like immune responses. However, there is limited knowledge about the complex network of intestinal and peripheral immune responses associated with the diseases. Aims: The aim of this thesis was to explore intestinal and peripheral immune responses in children at different stages of CD and in children with T1D. Further, we studied peripheral immune responses in children at risk for T1D supplemented with probiotics during their first 6 months of life (PRODIA study). Results & Discussion: Children with untreated CD had up-regulated T-helper (Th)1, T-cytotoxic (Tc)1, Th17 and T-regulatory (Treg) responses, but down-regulated Th2 and Th3 responses in the small intestine. The type 1 response (Th1 and Tc1) seemed to remain elevated in CD children under gluten free diet (GFD)-treatment and thus seemed to be related to the disease itself rather than the gluten intake. The Th2, Th3, Th17 and Treg responses seemed to be gluten dependent, since they normalized upon GFD-treatment. The alterations in the intestinal biopsies did not seem to correlate with the alterations seen in the blood Children with potential CD had diminished levels of the Th17 cytokine IL-17, whereas children with untreated CD had elevated levels of IL-17, indicating that IL-17 immunity develops in the late phase of CD when villous atrophy has developed. Furthermore, stimulation of intestinal epithelial cells with IL-17 induced anti-apoptotic mechanisms. The low intestinal expression of Th1, Th17 and Treg markers was normal in children with T1D, whereas children with T1D and CD had the same pattern as children with untreated CD: high intestinal secretion of pro-inflammatory and Th17 cytokines. The immune responses in children with T1D were generally influenced by the degree of villous atrophy. As expected, the number of children in the PRODIA study developing T1D related autoantibodies during their first two years of life was low. No difference in the autoantibody emergence was seen between infants given probiotics compared to placebo. In the probiotic group, the number of circulating CD58+ monocytes was lower at 6 months of age. At 12 months of age the number of circulating CCR5+ monocytes was lower in the probiotic group, whereas the spontaneous expression of TLR9 on PBMCs was higher. Conclusion: Most of the intestinal T-cell associated immune alterations were generally gluten dependent, since they normalized on a GFD treatment, but the type 1 response seemed to be related to the disease itself, since it was still seen in GFD treated individuals. IL-17 immunity seemed to be induced in the late stage of CD, when villous atrophy has developed and it seemed to be involved in protection from tissue damage in the inflamed intestinal mucosa. The intestinal immune responses were generally not reflected in peripheral blood. Probiotic supplementation in infancy modulated the activation stage and stimulation response of monocytes. Thus, early exposure to microbes seemed to influence the function of the innate immune system in later life

Establishing new principles for nutrient reference values (NRVs) for food labeling purposes

Many countries such as The Republic of Korea have established their own nutritional standards, collectively termed Nutrient Reference Values(NRVs), and they vary due to the science which was reviewed, the purposes for which they are developed, and issues related to nutrition and food policy in the country. The current effort by the Codex Alimentarius Committee on Nutrition and Foods for Special Dietary Uses (CNFSDU) to update the NRVs that were established following the Helsinki Consultation in 1988 represents an opportunity to develop a set of reference values reflecting current scientific information to be used or adapted by many countries. This paper will focus on possible approaches to selecting or developing reference values which would serve the intended purpose for nutrition labeling to the greatest extent possible. Within the United States, the Food and Drug Administration (U.S. FDA) is currently reviewing regulations on nutrition labeling to better address current health issues, and is expected to enter into a process in the next few months to begin to explore how best to update nutrient Daily Values (DVs), most of which are still based on the Recommended Dietary Allowances (RDAs) of the Food and Nutrition Board, U.S. National Academy of Sciences, last reviewed and revised in 1968. In this presentation, I review the current purposes in the U.S. for nutrition labeling as identified in the 1938 Food, Drug, and Cosmetic Act as amended, the scientific basis for current nutrition labeling regulations in the United States, and the recommendations made by the recent Committee on Use of Dietary Reference Intakes in Nutrition Labeling of the Institute of Medicine (2003) regarding how to use the DRIs in developing new DVs to be used on the label in the United States and Canada. Based on these reviews, I then provide examples of the issues that arise in comparing one approach to another. Much of the discussion focuses on the appropriate role of nutrient labeling within the Nutrition Facts panel, one of the three major public nutrition education tools in the United States (along with MyPyramid and Dietary Guidelines for Americans)

The Forest for the Trees: A Systems Approach to Human Health Research

We explore the relationship between current research directions in human health and environmental and public health policy. Specifically, we suggest there is a link between the continuing emphasis in biomedical research on individualized, therapeutic solutions to human disease and the increased reliance on individual choice in response to environmental and/or public health threats. We suggest that continued research emphasis on these traditional approaches to the exclusion of other approaches will impede the discovery of important breakthroughs in human health research necessary to understand the emerging diseases of today. We recommend redirecting research programs to interdisciplinary and population-focused research that would support a systems approach to fully identifying the environmental factors that contribute to disease burden. Such an approach would be able to address the interactions between the social, ecological, and physical aspects of our environment and explicitly include these in the evaluation and management of health risks from environmental exposures

EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on principles for deriving and applying Dietary Reference Values

This Opinion of the EFSA Panel on Dietetic products, Nutrition, and Allergies (NDA) deals with the general principles for development and application of Dietary Reference Values (DRVs). These quantitative reference values for nutrient intakes for healthy individuals and populations are based on health criteria. Derived from DRVs, nutrients goals and recommendations take into account other criteria such as food composition or dietary habits, and may be used for assessment and planning of diets. It is proposed to derive the following DRVs: 1) Population Reference Intakes (PRI), 2) Average Requirement (AR), 3) Lower Threshold Intake (LTI), 4) Adequate Intake (AI), 5) Reference Intake ranges for macronutrients (RI). Nutrient requirements differ with age, sex and physiological condition. The Panel proposes to define the age ranges used for each nutrient on a case-by-case basis depending on the available data. For the age group < 6 months requirements are considered to be equal to the supply from breast- milk, except in those cases where this does not apply. Separate reference values will be established for pregnant and lactating women. Interpolation or extrapolation between population groups will be used in instances where no data are available for defined age and sex groups