Zinc and vitamin A intake and status in a national sample of British young people aged 4–18 y

Abstract

Objective: To examine zinc and vitamin A intake and status and associated dietary, socio-demographic, lifestyle and physiological factors in British young people. Design: National Diet and Nutrition Survey of young people aged 4-18 y. Setting: Great Britain, 1997. Subjects: Complete 7-day weighed dietary records were provided by 1520 participants, while 1193 provided blood samples. Results: A total of 13 and 11% of participants respectively reported low dietary intakes of zinc and vitamin A (retinol equivalents), relative to the UK lower reference nutrient intake. These percentages were not altered significantly by including contributions to intake from supplements, mainly containing vitamin A (as retinol). Likelihood of low zinc and/or vitamin A intake was more often associated with age, sex and likely under-reporting of food consumption than with other sociodemographic and lifestyle factors. Low zinc and vitamin A intakes were generally less likely in those with higher consumption of dairy foods (mainly milk). Zinc and vitamin A status (assessed by plasma zinc and retinol concentrations) were adequate in almost all participants. Plasma zinc concentration was not significantly associated with zinc intake. Plasma retinol concentration was correlated with vitamin A intake (overall r ¼ 0.17, Po0.001; adjusted for age and plasma a 1 -antichymotrypsin concentration) and increased significantly with age (Po0.001) in both sexes. A significant association was found between plasma zinc and retinol concentrations in boys only (r ¼ 0.17, P ¼ 0.001). Conclusion: Zinc and vitamin A intakes and status were generally adequate in this national sample of British young people. Sponsorship:Food Standards Agency, UK.

Is the Mediterranean diet adequate to satisfy zinc requirements during adolescence?

“…Cereals, together with meat and dairy products, were the major contributors of dietary Zn, which is in agreement with previous studies conducted among Mediterranean adult populations in southern Spain (19) . Moreover, similar data have been reported in other epidemiological studies with adolescents in the UK (20) and Germany (21) , with children in New Zealand (22) and in the total Italian diet (23) . Fish and seafood, despite being important sources of Zn, made minor contributions to daily Zn intakes because these foods were partially rejected by some of the participants, which may account for their relatively low consumption (0?4 servings/d).…”

Plenary Lecture 3 Food and the planet: nutritional dilemmas of greenhouse gas emission reductions through reduced intakes of meat and dairy foods

“…Plasma Zn is not reported in the NDNS of adults but according to an analysis of the NDNS of children and adolescents, despite Zn intakes being below the RNI, Zn intakes and status appear to be generally adequate in young people aged 4-18 years (76) . The analysis shows that plasma Zn concentrations are 'low' in only 2 .…”

Is the zinc intake of young people in the UK adequate?

“…(b) The authors are incorrect in stating that tyrosine cannot be synthesized in brain from phenylalanine. (c) Despite the authors' statement, even very large increases in phenylalanine levels produced by aspartame administration to rats do not suppress catecholamine synthesis rate (Fernstrom et al, 1991) Dietary zinc intake in the investigation of 'zinc and vitamin A intake and status in a national sample of British young people aged 4-18 years' (Thane et al, 2004) was reported to be 'adequate' for most of the population. This conclusion was based on:…”

“…For example, 88 samples (8%) were collected from young people who had consented to the fasting procedure but had eaten or drunk something in the morning before blood sample was obtained (Gregory et al, 2000). (e) In this National Diet and Nutrition Survey, poor zinc status was defined as a concentration below 10.71 mmol l À1 for a fasting sample (Gregory et al, 2000;Thane et al, 2004). This cutoff point of zinc status was based on the data of the second National Health and Nutrition Examination Survey (Pilch and Senti, 1985) and the 10.71 mmol l À1 is a value derived from two standard deviations below the mean plasma zinc concentration for US adults.…”

“…Revised cutoff points based on age and gender will change the definition of 'low' plasma zinc concentration and population 'at risk' of zinc deficiency. (f) A total of 80% of the young people aged 4-18 years reported the dietary zinc intake below Reference Nutrient Intake, whereas 13% reported intake below their Lower Reference Nutrient Intake (Thane et al, 2004). Among subgroups, 26.2% of girls aged 4-6 years and 34.5% of girls aged 11-14 years had an intake below Lower Reference Nutrient Intake (Gregory et al, 2000).…”