Abstract
Background/objectives : Significant changes have been reported in dietary habits and food availability in Iceland that would be expected to compromise selenium intake and status, especially among young people. These include substantial decreases in the consumption of fish and milk, as well as the selenium content of imported wheat. The aim of this study was to assess selenium in the diet and whole blood of adolescent girls, as well as define the most important foods contributing to intake and blood concentrations of selenium.
Design : The subjects were 96 randomly selected girls, aged 16–20, who answered a validated food frequency questionnaire (FFQ) for dietary assessment. Selenium intake from each food group was calculated in µg/day. Blood samples were collected for measurement of whole blood selenium.
Results : Mean dietary selenium was 51±25 µg/day. Milk/dairy products, including cheese, contributed 36±14% of total dietary selenium; fish 18±12%; and bread/cereal products 13±6%. Mean whole blood selenium was 117±12 µg/l (range 90–208); nearly 90% of subjects were above the optimal level of 100 µg/l. Fish and bread/cereal products were the only foods significantly correlated with selenium in blood (r=0.32; P = 0.002 and r=0.22; P = 0.04, respectively) while no correlation was found with milk and dairy products in spite of their greater contribution to total selenium intake.
Conclusion : In this population of Icelandic adolescent girls, selenium intake and status seem acceptable. Judging from associations between intake and blood levels, fish and cereals may be the most important contributors to blood selenium.
Acknowledgements
The authors gratefully acknowledge the contribution of the study participants and the hospital and health clinic staff.
L.S. and I.G. were responsible for the study design, collection of data and interpretation of the results, and they supervised the writing of the paper. I.G. was also responsible for statistical analysis. A.T. was responsible for the measurements and analysis of the blood samples, O.R. for the Icelandic Food Composition Database and H.G. for food analysis. I.T. was involved in the study design, interpretation of the results and writing of the paper. E.Y.G. was involved in the data analysis and writing of the manuscript.