Vitamin A enrichment: Caution with encapsulation strategies used for food applications

Vitamin A is essential for life in mammals; it cannot be synthesized de novo and has to be provided by food. Vitamin A is poorly soluble in water and relatively unstable during food processing and storage. Numerous strategies have been developed to avoid its degradation, originally for pharmaceutical uses and now for nutritional applications. Day after day, increasing development of a lot of premixes containing appropriately protected concentrated vitamin A has been used in enriched and functional foods or in food supplements. We present an update of the principal techniques used for vitamin A encapsulation, their advantages and drawbacks and demonstrate that all of these could efficiently protect vitamin A and consequently, increase its bioavailability.On the other hand, in industrialized countries, vitamin A may be associated with sub-toxic effects due to its accumulation in the liver. Furthermore, it is now generally well agreed that the upper limit intake could be decreased for the elderly despite the known osteoporosis risk in the elderly and the fact that they are known to manifest impaired vitamin A metabolism. In parallel, the new roles of vitamin A in preventive nutrition against neurodegenerative diseases have recently increased the interest in supplementation via functional food or food supplements. This, associated with the increasingly frequent intake of vitamin A in food supplement or enriched food (i.e. with encapsulated vitamin A), leads us to the recommendation that more caution is necessary in the development of food strategies using vitamin A encapsulation, in industrialized countries.