Socio-economic determinants of micronutrient intake and status in Europe: a systematic review.

OBJECTIVE: To provide the evidence base for targeted nutrition policies to reduce the risk of micronutrient/diet-related diseases among disadvantaged populations in Europe, by focusing on: folate, vitamin B12, Fe, Zn and iodine for intake and status; and vitamin C, vitamin D, Ca, Se and Cu for intake. DESIGN: MEDLINE and Embase databases were searched to collect original studies that: (i) were published from 1990 to 2011; (ii) involved >100 subjects; (iii) had assessed dietary intake at the individual level; and/or (iv) included best practice biomarkers reflecting micronutrient status. We estimated relative differences in mean micronutrient intake and/or status between the lowest and highest socio-economic groups to: (i) evaluate variation in intake and status between socio-economic groups; and (ii) report on data availability. SETTING: Europe. SUBJECTS: Children, adults and elderly. RESULTS: Data from eighteen publications originating primarily from Western Europe showed that there is a positive association between indicators of socio-economic status and micronutrient intake and/or status. The largest differences were observed for intake of vitamin C in eleven out of twelve studies (5-47 %) and for vitamin D in total of four studies (4-31 %). CONCLUSIONS: The positive association observed between micronutrient intake and socio-economic status should complement existing evidence on socio-economic inequalities in diet-related diseases among disadvantaged populations in Europe. These findings could provide clues for further research and have implications for public health policy aimed at improving the intake of micronutrients and diet-related diseases.

EURRECA-Estimating iron requirements for deriving dietary reference values.

Currently, a factorial approach is used to derive reference values for iron. Calculations include the use of a bioavailability factor to convert the physiological requirement, derived from obligatory losses and requirements for growth and development, into a dietary intake value. A series of systematic reviews undertaken by the EURRECA Network of Excellence aimed to identify data that may increase the accuracy of factorial calculations across all population groups. The selection of robust data was guided by the use of standardized review methodology and the evidence-based selection of status biomarkers and dietary intake assessment techniques. Results corroborated the dearth of relevant factorial data, including whole-diet bioavailability data, and confirmed the need to continue extrapolating physiological requirements across population groups. Data were also unavailable that would allow reference values to be based on selected health outcomes associated with iron intake or status. Ideally, a series of observational and randomized controlled trial (RCT) studies need to be undertaken across all population groups and life stages to generate robust data for setting dietary reference values for iron. It will also be essential to include information on polymorphisms that potentially influence iron absorption and status in the derivation process.