Fortified Flour and The Bread and Flour Regulations 1998
By law any white wheat flour that is milled in the UK has to have calcium, iron and thiamin added. After the war the government decided that white flour needed the same vitamins as wholemeal flour. So for over 60 years we have added them to the flour (this is also done in Canada and USA, but they add folic acid as well).
The new EU labelling laws over-rode the UK legislation which made putting the vitamins in the ingredients list optional.
If you need unfortified/unenriched flour then use Wessex Mill French flour (the French flour is milled in France where they do not have to add the vitamins) or any of the wholemeal flours.
The labeling on bread will proably look like this.