Can plant-based diets put some people at risk of vitamin A deficiency? From in vitro and clinical approaches to action proposals – VITAVEGAN

Vitamin A (VA) comes from the consumption of retinol and its esters (found exclusively in animal products) and from proVA carotenoids (CAR) (mainly found in vegetables and fruits). With the current trend towards more plant-based diets in developed countries, the contribution of proVA CAR to VA intake is likely to increase sharply in the near future. Their bioavailability exhibits considerable variability, particularly due to the food matrix. Several compounds in plant-based foods (such as certain fibers or phytosterols) can decrease their bioavailability. Furthermore, their bioconversion into retinol shows strong interindividual variability, influenced by host factors such as single nucleotide polymorphisms (SNPs) in the gene coding for beta-carotene oxygenase 1 (BCO1). In individuals carrying these SNPs, insufficient intakes of bioavailable proVA CAR, not compensated by the consumption of preformed VA, as observed in consumers of plant-based diets, would increase the risk of VA deficiency. The project will be structured in 4 work packages (WP). In WP1, we will characterize the intake of VA and proVA CAR, the preparation methods of source foods, as well as purchasing strategies, in a model population of plant-based food consumers, specifically vegans (n=84), and omnivores (n=36). In WP2, we will measure, in a clinical study, the bioconversion of beta-carotene and the VA status of these 120 participants. We will evaluate the association of these phenotypes with SNPs in BCO1 among vegans and then compare the VA status between vegans and omnivores. In WP3, we will measure in vitro the bioaccessibility and intestinal absorption efficiency of proVA CAR from model vegan meals, testing the association of different protein sources. In WP4, we will communicate (to vegans, vegan associations, public health bodies, food suppliers) the obtained results to provide dietary recommendations aimed at increasing the intake of bioavailable proVA CAR for specific populations.