Proceedings of the Nutrition Society

Cambridge Journals Online - CUP Full-Text Page
Proceedings of the Nutrition Society (2010), 69:119-132 Cambridge University Press
Copyright © BGS/NERC 2009
doi:10.1017/S0029665109991807

Research Article

Symposium on ‘Geographical and geological influences on nutrition’ Factors controlling the distribution of selenium in the environment and their impact on health and nutrition

Conference on ‘Over- and undernutrition: challenges and approaches’

on 30 June–2 July 2009, The Summer Meeting of the Nutrition Society, was held at the University of Surrey, Guildford.


Christopher C. Johnsona1 c1, Fiona M. Fordycea2 and Margaret P. Raymana3

a1 British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
a2 British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, UK
a3 Nutritional Sciences Division, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
Article author query
johnson cc [PubMed]  [Google Scholar]
fordyce fm [PubMed]  [Google Scholar]
rayman mp [PubMed]  [Google Scholar]

Abstract

Se is essential to human and animal health but can be toxic in excess. An interest in its geochemistry has developed alongside a greater understanding of its function in a number of health conditions. Geology exerts a strong control on the Se status of the surface environment; low-Se rock-types (0·05–0·09 mg Se/kg) make up the majority of rocks occurring at the Earth's surface, which in turn account for the generally low levels of Se in most soils. However, there are exceptions such as associations with sulfide mineralisation and in some types of sedimentary rocks (e.g. black shales) in which contents of Se can be much higher. Baseline geochemical data now enable a comparison to be made between environmental and human Se status, although a direct link is only likely to be seen if the population is dependent on the local environment for sustenance. This situation is demonstrated with an example from the work of the British Geological Survey in the Se-deficiency belt of China. The recent fall in the daily dietary Se intake in the UK is discussed in the context of human Se status and declining use of North American wheat in bread making. Generally, US wheat has ten times more Se than UK wheat, attributed to the fact that soils from the wheat-growing belt of America are more enriched in Se to a similar order of magnitude. In agriculture effective biofortification of crops with Se-rich fertilisers must be demonstrably safe to the environment and monitored appropriately and baseline geochemical data will enable this process to be done with confidence.

(Online publication December 08 2009)

Key Words:Environmental Se; Human Se status; Se deficiency in China; Se intake in UK

Correspondence:

c1 Corresponding author: Dr Christopher C. Johnson, fax +44 1159 363 200, email ccj@bgs.ac.uk