Micronutrient deficiencies and overdoses

Health prevention includes an adequate dietary intake of macronutrients (carbohydrates, lipids, proteins) and micronutrients (vitamins, trace elements). Micronutrients play an essential role as co-factors or reducing agents in almost all of the biochemical reactions of cellular metabolism. The objective of this review is to provide an update of knowledge of the metabolism of the main micronutrients such as water-soluble (B1, B6, B9, B12, C) and fat-soluble (A, E, D) vitamins and trace elements (iron, zinc, copper, selenium) with a particular attention to their impact of inflammation. The aim of the review is also to define the status of micronutrients in groups at risk of emerging deficiency (inflammation bowel disease, bariatric surgery, bowel resection, COVID) and to draw out the main messages for putting them into practice. Biomarkers of micronutrient excess are generally less well characterized than those of deficiency, particularly in terms of links to functional or clinical symptoms of toxicity. The prevention of deficiencies in the absence of pathology, is based on a diet varied and balanced that easily covers all needs. Prevention by micronutritional supplements may be justified on a temporary or prolonged basis in particular pathophysiological situations (special diets, drug interactions, pathologies).(c) 2023 Societe francophone nutrition clinique et metabolisme (SFNCM). Published by Elsevier Masson SAS. All rights reserved.