E.L. Doets

Current micronutrient recommendations in Europe: towards understanding their differences and similarities

BackgroundNowadays most countries in Europe have established their own nutrient recommendations to assess the adequacy of dietary intakes and to plan desirable dietary intakes. As yet there is no standard approach for deriving nutrient recommendations, they may vary from country to country. This results in different national recommendations causing confusion for policy-makers, health professionals, industry, and consumers within Europe. EURRECA (EURopean micronutrient RECommendations Aligned) is a network of excellence funded by the European Commission (EC), and established to identify and address the problem of differences between countries in micronutrient recommendations. The objective of this paper is to give an overview of the available micronutrient recommendations in Europe, and to provide information on their origin, concepts and definitions. Furthermore this paper aims to illustrate the diversity in European recommendations on vitamin A and vitamin D, and to explore differences and commonalities in approaches that could possibly explain variations observed.MethodsA questionnaire was developed to get information on the process of establishing micronutrient recommendations. These questionnaires were sent to key informants in the field of micronutrient recommendations to cover all European countries/regions. Also the latest reports on nutrient recommendations in Europe were collected. Standardisation procedures were defined to enable comparison of the recommendations. Recommendations for vitamin A and vitamin D were compared per sex at the ages 3, 9 months and 5, 10, 15, 25, 50 and 70 years. Information extracted from the questionnaires and reports was compared focusing on: (1) The concept of recommendation (recommended daily allowance (RDA), adequate intake (AI) or acceptable range), (2) The year of publication of the report (proxy for available evidence), (3) Population groups defined, (4) Other methodological issues such as selected criteria of adequacy, the type of evidence used, and assumptions made.ResultsTwenty-two countries, the World Health Organization (WHO)/the Food and Agriculture Organization of the United Nations (FAO) and the EC have their own reports on nutrient recommendations. Thirteen countries based their micronutrient recommendations on those from other countries or organisations. Five countries, WHO/FAO and the EC defined their own recommendations. The DACH-countries (Germany, Austria and Switzerland) as well as the Nordic countries (Norway, Sweden, Finland, Denmark and Iceland) cooperated in setting recommendations. Greece and Portugal use the EC and the WHO/FAO recommendations, respectively and Slovenia adopted the recommendations from the DACH-countries. Rather than by concepts, definitions, and defined population groups, variability appears to emerge from differences in criteria for adequacy, assumptions made and type of evidence used to establish micronutrient recommendations.DiscussionThe large variation in current micronutrient recommendations for population groups as illustrated for vitamin A and vitamin D strengthens the need for guidance on setting evidence based, up-to-date European recommendations. Differences in endpoints, type of evidence used to set recommendations, experts’ opinions and assumptions are all likely to contribute to the identified variation. So far, background information was not sufficient transparent to disentangle the relative contribution of these different aspects.ConclusionEURRECA has an excellent opportunity to develop tools to improve transparency on the approaches used in setting micronutrient recommendations, including the selection of criteria for adequacy, weighing of evidence, and interpretation of data.

Vitamin B12, Folate, Homocysteine, and Bone Health in Adults and Elderly People: A Systematic Review with Meta-Analyses

Elevated homocysteine levels and low vitamin B12 and folate levels have been associated with deteriorated bone health. This systematic literature review with dose-response meta-analyses summarizes the available scientific evidence on associations of vitamin B12, folate, and homocysteine status with fractures and bone mineral density (BMD). Twenty-seven eligible cross-sectional (n = 14) and prospective (n = 13) observational studies and one RCT were identified. Meta-analysis on four prospective studies including 7475 people showed a modest decrease in fracture risk of 4% per 50 pmol/L increase in vitamin B12 levels, which was borderline significant (RR = 0.96, 95% CI = 0.92 to 1.00). Meta-analysis of eight studies including 11511 people showed an increased fracture risk of 4% per μmol/L increase in homocysteine concentration (RR = 1.04, 95% CI = 1.02 to 1.07). We could not draw a conclusion regarding folate levels and fracture risk, as too few studies investigated this association. Meta-analyses regarding vitamin B12, folate and homocysteine levels, and BMD were possible in female populations only and showed no associations. Results from studies regarding BMD that could not be included in the meta-analyses were not univocal.

B Vitamins and n–3 Fatty Acids for Brain Development and Function: Review of Human Studies

Background: Nutrition is one of many factors that affect brain development and functioning, and in recent years the role of certain nutrients has been investigated. B vitamins and n–3 polyunsaturated fatty acids (PUFA) are two of the most promising and widely studied nutritional factors. Methods: In this review, we provide an overview of human studies published before August 2011 on how vitamin B6, folate, vitamin B12 and n–3 PUFA may affect the brain, their nutrient status and the existing evidence for an association between these nutrients and brain development, brain functioning and depression during different stages of the life cycle. Results: No recommendation can be given regarding a role of B vitamins, either because the number of studies on B vitamins is too limited (pregnant and lactating women and children) or the studies are not consistent (adults and elderly). For n–3 PUFA, observational evidence may be suggestive of a beneficial effect; however, this has not yet been sufficiently replicated in randomized controlled trials (RCTs). Conclusions: We found that the existing evidence from observational studies as well as RCTs is generally too limited and contradictory to draw firm conclusions. More research is needed, particularly a combination of good-quality long-term prospective studies and well-designed RCTs.

Prioritizing micronutrients for the purpose of reviewing their requirements: a protocol developed by EURRECA

Background:The EURRECA (EURopean micronutrient RECommendations Aligned) Network of Excellence (http://www.eurreca.org) is working towards the development of aligned recommendations. A protocol was required to assign resources to those micronutrients for which recommendations are most in need of alignment.Methods:Three important ‘a priori’ criteria were the basis for ranking micronutrients: (A) the amount of new scientific evidence, particularly from randomized controlled trials; (B) the public health relevance of micronutrients; (C) variations in current micronutrient recommendations. A total of 28 micronutrients were included in the protocol, which was initially undertaken centrally by one person for each of the different population groups defined in EURRECA: infants, children and adolescents, adults, elderly, pregnant and lactating women, and low income and immigrant populations. The results were then reviewed and refined by EURRECAs population group experts. The rankings of the different population groups were combined to give an overall average ranking of micronutrients.Results:The 10 highest ranked micronutrients were vitamin D, iron, folate, vitamin B12, zinc, calcium, vitamin C, selenium, iodine and copper.Conclusions:Micronutrient recommendations should be regularly updated to reflect new scientific nutrition and public health evidence. The strategy of priority setting described in this paper will be a helpful procedure for policy makers and scientific advisory bodies.

Vitamin B12 Intake and Status and Cognitive Function in Elderly People

Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 μg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimers disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status.

Nutri-RecQuest: a web-based search engine on current micronutrient recommendations

Background:The EURRECA (EURopean micronutrient RECommendations Aligned) Network of Excellence collated current micronutrient recommendations. A user-friendly tool, Nutri-RecQuest, was developed to allow access to the collated data and to create a database source for use in other nutritional software tools.Methods:Recommendations, that is, intakes of micronutrients sufficient to meet the requirements of the majority of healthy individuals of that population, from 37 European countries/organizations and eight key non-European countries/regions comprising 29 micronutrients were entered into a database. General information on the source of the recommendations, as well scientific background information, was added.Results:A user-friendly web-based interface was developed to provide efficient search, comparison, display, print and export functions.Conclusion:Easy access to existing recommendations through the web-based tool may be valuable for bodies responsible for setting recommendations, as well as for users of recommendations including scientists, policy makers, health professionals and industry. Adding related dietary reference values such as average nutrient requirements and upper limits may extend the utility of the tool.

European micronutrient recommendations aligned: a general framework developed by EURRECA

Background:In Europe, micronutrient recommendations have been established by (inter)national committees of experts and are used by public health-policy decision makers to monitor and assess the adequacy of the diets of population groups. Current micronutrient recommendations are, however, heterogeneous, whereas the scientific basis for this is not obvious. Alignment of setting micronutrient recommendations is necessary to improve the transparency of the process, the objectivity and reliability of recommendations that are derived by diverse regional and (inter)national bodies.Objective:This call for alignment of micronutrient recommendations is a direct result of the current sociopolitical climate in Europe and uncovers the need for an institutional architecture. There is a need for evidence-based policy making, transparent decision making, stakeholder involvement and alignment of policies across Europe.Results:In this paper, we propose a General Framework that describes the process leading from assessing nutritional requirements to policy applications, based on evidence from science, stakeholder interests and the sociopolitical context. The framework envisions the derivation of nutrient recommendations as scientific methodology, embedded in a policy-making process that also includes consumer issues, and acknowledges the influences of the wider sociopolitical context by distinguishing the principal components of the framework: (a) defining the nutrient requirements for health, (b) setting nutrient recommendations, (c) policy options and (d) policy applications.Conclusion:The General Framework can serve as a basis for a systematic and transparent approach to the development and review of micronutrient requirements in Europe, as well as the decision making of scientific advisory bodies, policy makers and stakeholders involved in this process of assessing, developing and translating these recommendations into public health nutrition policy.

Explaining the variability in recommended intakes of folate, vitamin B12, iron and zinc for adults and elderly people

OBJECTIVE To signal key issues for harmonising approaches for establishing micronutrient recommendations by explaining observed variation in recommended intakes of folate, vitamin B12, Fe and Zn for adults and elderly people. DESIGN We explored differences in recommended intakes of folate, vitamin B12, Fe and Zn for adults between nine reports on micronutrient recommendations. Approaches used for setting recommendations were compared as well as eminence-based decisions regarding the selection of health indicators indicating adequacy of intakes and the consulted evidence base. RESULTS In nearly all reports, recommendations were based on the average nutrient requirement. Variation in recommended folate intakes (200-400 μg/d) was related to differences in the consulted evidence base, whereas variation in vitamin B12 recommendations (1.4-3.0 μg/d) was due to the selection of different CV (10-20 %) and health indicators (maintenance of haematological status or basal losses). Variation in recommended Fe intakes (men 8-10 mg/d, premenopausal women 14.8-19.6 mg/d, postmenopausal women 7.5-10.0 mg/d) was explained by different assumed reference weights and bioavailability factors (10-18 %). Variation in Zn recommendations (men 7-14 mg/d, women 4.9-9.0 mg/d) was also explained by different bioavailability factors (24-48 %) as well as differences in the consulted evidence base. CONCLUSIONS For the harmonisation of approaches for setting recommended intakes of folate, vitamin B12, Fe and Zn across European countries, standardised methods are needed to (i) select health indicators and define adequate biomarker concentrations, (ii) make assumptions about inter-individual variation in requirements, (iii) derive bioavailability factors and (iv) collate, select, interpret and integrate evidence on requirements.

Physiological and public health basis for assessing micronutrient requirements in children and adolescents. The EURRECA network

This paper provides an overview of the current knowledge relating to the nutritional requirements and corresponding recommended nutrient intake values of children and adolescents for micronutrients and specificities related to these requirements in the course of childhood and adolescence in Europe. Aspects that can influence micronutrient requirements, such as physiological requirements and bioavailability of the nutrients in the organism, are discussed. The methodology used to obtain the data and also the main knowledge gaps regarding these concepts are emphasized. Methodological critical points in achieving the data and physiological aspects of children and adolescents are important in order to standardize the reference values for micronutrients among Europe for these stages of life.

The nutritional requirements of infants. Towards EU alignment of reference values : the EURRECA network

This paper presents a review of the current knowledge regarding the macro- and micronutrient requirements of infants and discusses issues related to these requirements during the first year of life. The paper also reviews the current reference values used in European countries and the methodological approaches used to derive them by a sample of seven European and international authoritative committees from which background scientific reports are available. Throughout the paper, the main issues contributing to disparities in micronutrient reference values for infants are highlighted. The identification of these issues in relation to the specific physiological aspects of infants is important for informing future initiatives aimed at providing standardized approaches to overcome variability of micronutrient reference values across Europe for this age group.