Regulation (EC) No 1925/2006 on the addition of vitamins and minerals and of certain other substances to foods has been assimilated into national law. However, it only applies in GB, with NI following the EU Regulation (EC) No 1925/2006 directly. Since the end of the transitional period (when the UK effectively took a 'snapshot' of EU law and converted it into Re-tained EU Law) the UK has not made any amendments to this Regulation, except to make it operable in the UK (i.e. remove/replace references to EU/EU committees). However, the EU Regulation has been amended several times; it has expanded the list of prohibited substances (aloe-emodin, emodin, danthron and aloe extracts containing hydrox-yanthracene derivatives); added to the list of restricted substances (monacolins from red yeast rice and green tea extracts containing (-)- epigallocatechin-3-gallate) and included nicotinamide riboside chloride as a permitted form of niacin. Because these changes apply in NI but not in GB, there is intra-UK divergence, meaning that a fortified product containing, say, one of the newly prohibited substance could be permitted in GB but prohibited in NI. Fortu-nately, the newly prohibited and restricted substances in the EU/NI are not common in the UK, but as time goes by and EU and GB Regulations evolve, increased divergence is inevitable, posing new challenges for food businesses wanting to market products in the EU/NI and GB.