Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian diets

Eveleigh, Elizabeth; Coneyworth, Lisa; Welham, Simon

Abstract

Vegan and vegetarian diets are widely supported and adopted, but individuals following such diets remain at greater risk of iodine deficiency. This systematic review and meta-analysis was conducted to assess the iodine intake and status in adults following a vegan or vegetarian diet in the modern day. A systematic review and quality assessment were conducted from October 2020-December 2022 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidance. Studies were identified in Ovid MEDLINE, Web of Science, PubMed, and Scopus. Eleven articles were eligible for review containing 4,421 adults (aged ≥ 18 years). Vegan groups had the lowest median urinary iodine concentration (mUIC) (12.2 L-1). None of the dietary groups had mUIC within the optimal range for iodine status (100-200 μg L-1) (World Health Organisation). Vegan diets had the poorest iodine intake (17.3 μg day-1) and were strongly associated with lower iodine intake (P = < 0.001) compared to omnivorous diets. Lower intake in vegan diets were influenced by gender (P = 0.007), the presence of voluntary or absence of Universal Salt Iodisation (USI) programmes (P = 0.01 P = < 0.001), and living in a country with adequate iodine nutrition (P = < 0.001). Vegetarians and particularly vegans, living in countries with no current USI programme continue to have increased risk of low iodine status, iodine deficiency and inadequate iodine intake. Further research into the usefulness of mandatory fortification of vegan appropriate foods is required.

Citation

Eveleigh, E., Coneyworth, L., & Welham, S. (2023). Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian diets. British Journal of Nutrition, 130(9), 1580-1594. https://doi.org/10.1017/S000711452300051X

• Journal Article Type: Article
• Acceptance Date: Feb 21, 2023
• Online Publication Date: Mar 13, 2023
• Publication Date: Nov 14, 2023
• Deposit Date: Mar 20, 2023
• Publicly Available Date: Sep 14, 2023
• Journal: British Journal of Nutrition
• Print ISSN: 0007-1145
• Electronic ISSN: 1475-2662
• Publisher: Cambridge University Press
• Peer Reviewed: Peer Reviewed
• Volume: 130
• Issue: 9
• Pages: 1580-1594
• DOI: https://doi.org/10.1017/S000711452300051X
• Keywords: Iodine; Iodine intake; Micronutrients; Vegan; Vegetarian
• Public URL: https://nottingham-repository.worktribe.com/output/18767202
• Publisher URL: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/systematic-review-and-metaanalysis-of-iodine-nutrition-in-modern-vegan-and-vegetarian-diets/BDF76B702760D9297E2A0E8E40F2494B