In March 2018 researchers from the UK and Germany published the results of their study to assess the effect of increased cow’s milk consumption on iodine status, thyroid hormone levels, and selenium status. This study was undertaken due to recent evidence which has shown that women of childbearing age and those who are pregnant are prone to mild-to-moderate iodine deficiency, which is important as iodine is required for thyroid hormone production and for neurodevelopment. A total of 78 women, aged 18-45 years, who had a low to moderate intake of milk were included in the study and followed for a 12-week period. The women were divided into two groups, with one group consuming 3 litres of semi-skimmed milk per week and the other continuing with their usual milk intake. Iodine and thyroid levels and selenium status were assessed at the start of the study, at 6 weeks and at the end of the study. Results showed that those consuming the 3L of semi-skimmed milk per week experienced increasing levels of iodine over the course of the study and that iodine levels were significantly greater in this group than those who remained on their normal milk intake. However, over this 12-week period no significant differences in thyroid levels or selenium status was noted between the two groups.
O’Kane SM et al. Cow Milk Consumption Increases Iodine Status in Women of Childbearing Age in a Randomized Controlled Trial. J Nutr. 2018 Mar 1;148(3):401-408