Variation in nutritional quality in UK retail eggs.

Fatty acid (FA), carotenoid and vitamin contents of UK eggs were assessed for four production systems (caged (CA), free-range (FR), organic (OR) and extensive organic (EO)) as well as season. The impact of enforced housing, due to avian influenza, was also investigated. Production system did not alter vitamin D 3 , B 2 or B 9 content, but significantly influenced nutritionally desirable FA, carotenoid and vitamins A and E - concentrations decreased as production intensity increased, although for most, CA and FR did not differ significantly. Vitamin E and FA profiles for OR and EO were also similar, although carotenoids were higher in EO eggs. In contrast, FA, carotenoids, vitamins E and B 9 were consistent throughout the year, unlike vitamins A, D 3 and B 2 , which fluctuated with season; D and B 2 were higher in July than January and lower vitamin A was the only detected implication from enforced housing of FR and OR birds. • Fatty acid, carotenoid and vitamins in eggs from caged, free range and organic hens • Eggs from free range and caged systems were very similar • Nutrients in organic eggs were higher than free range and cage eggs • Vitamins A, E, B 9 , carotenoids and fatty acids were consistent throughout the year • Vitamin D and B 2 were higher in summer than winter [ABSTRACT FROM AUTHOR]