In January 2018 researchers from the UK published the results of their study to assess the iodine content of conventional, organic and UHT semi-skimmed milk as milk is the largest source of iodine in the UK diet. Conventional, organic and UHT semi-skimmed milk was bought from four supermarkets over a six-month period in summer and winter in two regions of the UK. Results showed organic milk to be 44% lower in iodine than conventional milk and UHT semi-skimmed milk 27% lower in iodine although the differences tended to be less in the summer. Replacing conventional milk with organic or UHT semi-skimmed milk will increase the risk of low iodine status.
Stevenson MC et al. Further studies on the iodine concentration of conventional, organic and UHT semi-skimmed milk at retail in the UK. Food Chem. 2018 Jan 15;239:551-555