The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal BMJ Nutrition, Prevention & Health. To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient — choline — found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specializing in nutrition and biomedical science. Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body. choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire. The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.