Increasing numbers of people are following vegetarian and vegan diets in which some key nutrients may be deficient. Screening for common deficiencies should be considered, as well as other potential causes or contributors.
- Vegetarian and vegan diets can provide adequate nutrition but may require additional planning, particularly for those transitioning to such diets for the first time.
- Assessing whether nutrition is adequate is particularly important for vegans and for patients during pregnancy and while breastfeeding due to increased requirements.
- It is important to screen for common nutrient deficiencies (in particular vitamin B12 deficiency in vegans, given its prevalence).
- All. deficiency may not be due to diet alone; alternative causes or contributors should be considered.
- For those eating a more limited range of foods, a complete multivitamin can help meet daily requirements, but specific supplementation may be required.
Plant-based diets have continued to garner increased interest and be adopted by the general population due to their well-established health and environmental benefits.1-3 Plant-based diets reduce or completely avoid the consumption of foods sourced from animals. This encompasses a range of individual diets, which are summarised in Table 1. From a global perspective, the EAT-Lancet commission highlights the benefits of a larger scale adoption of a plant-based diet, estimating that up to 24% of total deaths among adults could be prevented while also improving planetary health through a reduction in greenhouse gas emissions and more efficient cropland and water usage.3 Overall, the key to any healthy plant-based diet is the focus on nutrient-dense plant foods that are generally lower in saturated fat and the avoidance of refined carbohydrates. This article focuses on managing patients on vegetarian and vegan diets rather than a flexitarian diet.
The current numbers of Australians eating a vegetarian or vegan diet are not well established. The last national government- conducted survey specifically looking at special diets was undertaken in 1995.4 Of all respondents, 3.7% reported being on a vegetarian diet, with a higher proportion being female (4.9% vs 2.6%), and of these, over 5% were aged 16 to 44 years. More recently, the Roy Morgan research group estimated that 12.1% of the population in 2018 ate a mostly vegetarian diet, up from 11.2% in 2014 and 9.7% in 2012, with the largest demographic being young, educated people.5 Perhaps a greater global awareness, concern for animal welfare, and/or easy access to like-minded people and groups through social media, rather than health or religious reasons, drives this.