Diet study finds many vegans may severely lack iodine, but not B12

Plant-based diets, including vegan ones, are growing in popularity as the public becomes more conscious of dietary impacts on the environment and health. The trend away from animal-based products has raised some questions and concerns about the potential health consequences of plant-based diets, ones mostly revolving around nutrients and the struggles one may face when only consuming plant foods.

Vegan diets are popularly associated with B12 deficiency for one simple reason: this critical nutrient comes from animal-based products like eggs and meat. Someone who eats a purely plant-based diet must supplement with B12 to avoid deficiency, which may lead to nerve problems and more.

Awareness of this critical need has led to the rise of fortified foods, such as nutritional yeast with add B12, targeted at vegans. It's no surprise, then, that a new study out of Germany found that vegans and omnivores had no differences in biomarkers for B12, as well as vitamin D and iron (three omnivores and four vegans in study had iron deficiency).

However, the study did find a different deficiency that impacted a significant number of vegans who participated in the research: iodine. Vegans were found to have 'markedly lower' levels of iodine compared to non-vegans, and a full third of the vegan participants met WHO's criteria for severe iodine deficiency.

The researchers note that sufficient B12 levels may be due to vegans taking supplements to keep their levels optimal. However, vegans may struggle with getting adequate iodine intake, potentially leading to the development of hypothyroidism. That issue aside, the study notes some potential benefits from a vegan diet, including lowered saturated fatty acid and cholesterol consumption which may help protect heart health.