The impact of replacing milk with plant-based alternatives on iodine intake: a dietary modelling study

Abstract

Purpose: Cow’s milk is the primary source of iodine in the UK, but consumption of plant-based milk alternatives (PBMA) is increasing and these products are often not fortified with iodine. We evaluated the impact that replacing current milk consumption with PBMA would have on iodine intake. Methods: We used data from the National Diet and Nutrition Survey (2016–2019) for children (1.5–10 years), girls 11–18 years, and women of reproductive age (WRA). We used a dietary modelling approach with scenarios using brand-level iodine-fortification data (0, 13, 22.5, 27.4 and 45 µg/100 mL). Relative to usual diet, we calculated change in iodine intake, and the proportion with intake below the Lower Reference Nutrient Intake (LRNI) or above the upper limit. Results: For all groups, replacement with PBMA, either unfortified or fortified at the lowest concentration, resulted in a meaningful decrease in iodine intake, and increased the proportion with intake < 45 µg iodine/100 mL would be required to minimize the impact on iodine intake. Research is needed on the impact of total dairy replacement.