Plain language summary
Plant based diets, especially veganism have become increasingly popular all over the world. Changing from an omnivorous to a vegan or vegetarian diet has been associated with various health benefits; however, these dietary patterns are also linked to an increased risk of micronutrient deficiency. Iodine is a trace element which is needed to produce thyroid hormones and therefore maintain normal physiological functions of the body. In Norway, the main dietary sources of iodine are milk, seafood and eggs. The aim of this study was to evaluate iodine status, dietary intake of iodine, supplement use, macroalgae use and iodine knowledge of Norwegian vegans, vegetarians and pescatarian. Vegans, vegetarians and pescatarians in Norway are at risk of iodine deficiency and have limited knowledge of iodine. They were unable to reach recommended iodine intake from food sources alone. Data is needed on thyroid function in vegans, vegetarians and pescatarians to fully understand the consequences of iodine supplement use or macro algae use when adhering to a vegan, vegetarian or pescatarian diet in Norway.
Abstract
Low iodine intakes have been documented in different population groups in Norway. We aimed to assess iodine status, dietary intake, supplement and macroalgae use, and iodine knowledge in vegans, vegetarians and pescatarians. In this study, 115 vegans, 55 vegetarians and 35 pescatarians from the Oslo region of Norway, aged 18-60 years, participated. A spot urine sample was collected along with a dietary assessment of iodine intake, supplement and macroalgae use. The median urinary iodine concentration (MUIC) in vegans was 43 µg/L (moderate iodine deficiency), in vegetarians 67 µg/L and in pescatarians 96 µg/L (mild iodine deficiency). In multiple linear regression analysis, use of iodine supplements was one of the strongest predictors of UIC. About half of the participants had median 24-h iodine intakes below estimated average requirement (EAR) of 100 µg/day. Fifty percent had low knowledge score, while 27% had very low knowledge score. Vegans, vegetarians and possibly pescatarians in Norway, are unable to reach the recommended iodine intake merely from food and are dependent on iodine supplements. There is an urgent need for dietary guidance targeting vegans, vegetarians and pescatarians to avoid inadequate iodine intake in non-supplement users, as well as avoiding excess iodine intake in macroalgae users.
Methodological quality
Jadad score
:
Not applicable
Allocation concealment
:
Not applicable
