Contribution of plant-based dairy and fish alternatives to iodine nutrition in the Swiss diet: a Swiss Market Survey.

Abstract

With dairy products and fish being major sources of iodine in Switzerland, the growing popularity of plant-based alternatives may impact iodine nutrition. This study aimed to assess the iodine content in plant-based dairy and fish alternatives available in the Swiss market and compare them with conventional products. In 2022, a market survey was conducted in Zurich, Switzerland, to identify the plant-based dairy and fish alternatives available and assess their iodine content. To evaluate the impact of plant-based alternatives on iodine consumption in Switzerland, we modeled dietary scenarios by substituting the intake of dairy and fish items with plant-based alternatives. In addition, we investigated fortification with calcium, vitamins B2, B12, and D. Out of 477 identified products, only four milk-alternative products were iodine fortified (median iodine concentration: 22.5 μg/100 ml). The median iodine concentration in unfortified plant-based alternatives was negligible compared to conventional dairy and fish products (milk: 0.21 vs 9.5 μg/100 ml; yogurt 0.36 vs 6.1 μg/100 g; cheese: 0.10 vs 20 μg/100 g; fish 0.50 vs 44 μg/100 g). Three portions of dairy per day as recommended by the Swiss Food Pyramid provide 25% of the RDA for iodine (150 μg/day), whereas substituting those with unfortified alternatives provides only 0.7% of the RDA. Only four out of 477 plant-based alternative products are iodine fortified in the Swiss market. Thus, the risk for consumers to miss out on the ca. 25% of the RDA for iodine by consuming plant-based alternatives is high, placing them at a risk for inadequate iodine intake.