Why do foods have such vastly different nutrient contents in different databases?

Minerva_McGonagall

I just had occasion to consider the vitamin E content of 100g egg yolk. The entry for raw egg, yolk on Cronometer says 2.6 mg, but the entry in the Swedish National Food Agency’s database says 16.7 mg! Are Swedish eggs really more nutritious or is this a huge error somewhere?
You can find the database here:
http://www7.slv.se/SokNaringsinnehall/Home/FoodDetails/1226#

Karen_Cronometer

Nutrient composition of foods can vary geographically, in this case likely due to differences in agricultural practices between the two regions. For example, standard chicken feed in the US may contain lower vitamin E than what is typically used in Sweden, resulting in lower vitamin E content in the egg yolk.