Nutritional requirements during lactation. Towards European alignment of reference values: the EURRECA network.
ABSTRACT There is considerable variation in reference values for micronutrient intake during lactation across Europe. The European Micronutrients Recommendations Aligned project aims to harmonize dietary recommendations throughout Europe. Recommended nutrient intakes during lactation are based on limited data and are often extrapolated from known secretion of the nutrient in milk with adjustments for bioavailability, so that differences between values can be partly ascribed to differences in methodological approaches and how these approaches were applied. Few studies have considered the impact of lactation on the mother's nutritional status. Rather, focus has been placed on the influence of maternal nutritional status on the composition of her breast milk. Most common nutritional deficits in breast milk are the result of maternal deficiencies of the water-soluble vitamins, thiamine, riboflavin and vitamins B6 and B12. Other than maternal vitamin A status, which to some extent is reflected in breast milk, concentrations of fat-soluble vitamins and most minerals in breast milk are less affected by maternal status. Factors relating to suboptimal maternal nutritional status during lactation include maternal age, diet and lifestyle factors and spacing of consecutive births. Recent research is providing new knowledge on the micronutrient requirements of lactating women. Identifying needs for research and improving understanding of the differences in values that have been derived by various committees and groups across Europe will enhance transparency and facilitate the application of dietary recommendations in policy-making decision and their translation into recommendations for lactating women. Given the wide variation in breastfeeding practices across Europe, making nutritional recommendations for lactating women is complex and challenging. Thus, it is crucial to first examine the cultural practices within and across European populations and to assess its relevance before making recommendations.
Article: The relationship between zinc intake and serum/plasma zinc concentration in pregnant and lactating women: a systematic review with dose-response meta-analyses.[show abstract] [hide abstract]
ABSTRACT: Recommendations for zinc intake during pregnancy and lactation vary widely across Europe. Using data on zinc intake and biomarkers of zinc status reported in randomized controlled trials (RCTs) and observational studies can provide estimates of dose-response relationships that may be used for underpinning zinc reference values. This systematic review included all RCTs, prospective cohort studies, nested case-control studies and cross-sectional studies in healthy pregnant and lactating populations published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient (βˆ) was calculated for each individual study and calculated the overall pooled βˆ and SE (βˆ) using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status found that a doubling of zinc intake was associated with an increase in serum/plasma zinc status by 3% in pregnant women and by 1% in lactating women. These modest associations are likely to reflect the low-moderate zinc bioavailability dietary patterns and the widespread use of other micronutrients in the populations included in this review, physiologic adjustments of zinc homeostasis, insensitivity of serum/plasma zinc as a biomarker of zinc status, and wide heterogeneity between study results which reflect real uncertainty in the current evidence base. Although this review provides useful information for dietary zinc requirements in populations vulnerable to zinc deficiency, it also highlights a need for further studies in pregnant and lactating women with different dietary patterns in order to provide useful complementary evidence that can be utilized when setting zinc recommendations as a basis for nutrition policies in Europe.Journal of Trace Elements in Medicine and Biology 05/2012; 26(2-3):74-9. · 1.68 Impact Factor