“…Finally, it is important to consider that a number of factors can affect the vitamin A absorption and availability and thus its requirements, including the presence and severity of infection and parasites, intestinal or liver disease (such as biliary atresia, cholangitis, viral hepatitis, alcoholic liver disease and non-alcoholic fatty liver disease), iron and zinc status, stress, fat intake, xenobiotics, protein energy malnutrition, alcohol consumption and the food matrix and food processing. Both insufficient dietary retinoid intake (hypovitaminosis A or VAD) and excessive retinoid consumption resulting in vitamin A concentrations above the physiological range (hypervitaminosis A or vitamin A-toxicity) cause adverse effects to human health, which are paradoxically similar in both situations [ 24 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ].…”