Vegans and vegetarians living in Nottingham (UK) continue to be at risk of iodine deficiency

Detecting iodine deficiency risks from dietary transitions using shopping data

Plant-based product replacements are gaining popularity. However, the long-term health implications remain poorly understood, and available methods, though accurate, are expensive and burdensome, impeding the study of sufficiently large cohorts. To identify dietary transitions over time, we examine anonymised loyalty-card shopping records from Co-op Food, UK. We focus on 10,626 frequent customers who directly replaced milk with alternative milk. We then use product nutritional information to estimate weekly nutrient intake before and after the transition. 83% who converted to alternative milk saw a fall in iodine (44%), calcium (30%) and vitamin B12 (39%) consumption, with 57% reducing iodine purchase by more than 50%. The decline is even higher for those switching dairy and meat products. Our findings suggest that dietary transitions - such as replacing milk with alternative milk - could lead to nutritional deficiencies, notably iodine, which, if not addressed, may represent a significant public health concern, particularly in countries which do not mandate salt iodisation.

Adoption of a Short-Term (4-Week) Vegan Diet as Part of 'Veganuary' Significantly Reduces Saturated Fatty Acid (SFA), Cholesterol, B12, and Iodine Intake in Omnivorous Individuals-An Observational Study

Global veganism campaigns like 'Veganuary' have gained popularity. We conducted an observational study to assess the impact of a 4-week vegan diet during 'Veganuary' on nutrient intake, status, knowledge, and motivations for veganism. Data were collected before and after 'Veganuary', using Food Frequency Questionnaires (FFQs) to estimate dietary intake. Micronutrient knowledge and motivation were assessed through questionnaires. A total of 154 UK adults aged 18-60 years (2019: n81; 2020: n73) participated. Groups were vegetarians and omnivores committed to a 4-week vegan diet during 'Veganuary'. Control groups were vegans and omnivores who did not transition. Short-term vegan diets significantly decreased intake of iodine, B12, cholesterol, and saturated fatty acids (SFAs) in omnivores. Micronutrient knowledge was low, and motivation for veganism varied. Short-term vegan diets reduce macro- and micronutrient intake in omnivores. Veganuary participants could benefit from nutritional guidance or supplementation. Attention is required for UK micronutrient intake and knowledge. Motivations for vegan pledges may influence diets, warranting further research.

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

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 to 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 4421 adults (aged ≥ 18 years). Vegan groups had the lowest median urinary iodine concentration (mUIC) (12·2/l). None of the dietary groups had mUIC within the optimal range for iodine status (100-200 µg/l) (WHO). Vegan diets had the poorest iodine intake (17·3 µg/d) and were strongly associated with lower iodine intake (P = < 0·001) compared with omnivorous diets. Lower intake in vegan diets was influenced by sex (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.

The Antioxidant Properties of Selected Varieties of Pumpkin Fortified with Iodine in the Form of Potassium Iodide and Potassium Iodate

This study aimed to investigate the use of selected pumpkin varieties as carriers of potassium iodide (KI) and potassium iodate (KIO₃) at different concentrations (2.3, 0.23, and 0.023 mg/100 g). It was hypothesized that the concentrations and form of iodine fortification in pumpkins affect the antioxidant activity of pumpkins. The results showed a high recovery of the introduced iodine in all pumpkin varieties after drying, as well as high iodine stability during storage, especially for KIO₃. However, statistical analysis confirmed a relationship between the forms and concentration of iodine and the ABTS cation radical and the DPPH radical test results. In the systems with iodine concentration at 0.023 and 0.23 mg/100 g, the antioxidant activity did not change. However, for all pumpkin varieties fortified with a KIO₃ concentration at 3.9 mg/100 g (2.3 mg/100 g of iodine), a statistically significant decrease in free-radical scavenging was confirmed. Therefore, for maximum effectiveness in pumpkin's free-radical scavenging indices, it is suggested to introduce iodine in the form of KI and KIO₃, but in controlled concentrations. However, KIO₃ should be added at a maximum amount of 0.39 mg/100 g.

The Effect of a Vegan Diet on the Coverage of the Recommended Dietary Allowance (RDA) for Iodine among People from Poland

The aim of this research was to estimate the effect of a vegan diet on the Recommended Dietary Allowance (RDA) coverage for iodine in people from Poland. It was hypothesized that the problem of iodine deficiency is a concern, especially among vegans. The survey study was conducted in the years 2021-2022 on 2200 people aged 18-80 with omnivore and vegan diets. The exclusion criteria in the study were pregnancy and lactation. The study found that the coverage of RDA for iodine among people with a vegan diet was lower than among people with an omnivore diet (p < 0.05); 90% of the participants with a vegan diet had an iodine intake below 150 µg/day. Plant-based dairy and meat analogs were consumed by vegans frequently and in large portions, but none were fortified with iodine. It was found that iodized salt was each group's primary source of iodine. However, it was observed that the iodine supply from this source was limited among vegans, especially in female subjects, who consumed less salt and smaller portions of meals. That is why consideration should be given to the iodine fortification of plant-based foods commonly consumed by vegans.