Zinc intake and status in Austria in the light of different reference values

Int J Vitam Nutr Res. 2017 May;87(3-4):169-178. doi: 10.1024/0300-9831/a000484. Epub 2019 Feb 1.

Abstract

Zinc has been identified as a critical micronutrient also in high-income countries. There is still some uncertainty about the evaluation of zinc sufficiency due to divergent daily intake reference values. We wanted to exemplify this issue using data from the Austrian Study on Nutritional Status 2012. Plasma zinc concentrations were measured in a nationally representative sample of 872 persons aged 6-80 years (55.5 % female). Dietary zinc intake was estimated from two 24h dietary recalls. Additionally, parameters of the antioxidative status (plasma malondialdehyde (MDA), total antioxidative capacity) and activities of alkaline phosphatase (AP), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)) were determined. Zinc status was marginal in schoolchildren (40 % of boys and 22 % of girls) and in elderly (28 % of men and 33 % of women). Dietary zinc intake was also unsatisfactory in these groups with 38 % of boys and 32 % of girls and 64.5 % of older men below the nationally recommended intake levels. However, the adequacy of zinc intake varied with different reference values. Adults were more likely to meet the D-A-CH reference values and those from the European Food Safety Authority than the recommendations of the International Zinc Nutrition Consultative Group (IZiNCG) and the Institute of Medicine, whereas children met the IZiNCG values best. Zinc status correlated weakly with AP activity (r = -0.298, p < 0.001) and some antioxidant status markers (CAT, MDA, GSH-PX, SOD), especially in the elderly (MDA: r = -0.527, p < 0.001, and SOD: r = -0.466, p = 0.002). Our results suggest a suboptimal zinc supply in Austria particularly among schoolchildren and older adults.

Keywords: Zinc; antioxidant status; dietary intake; reference values; status.