Meeting the Vitamin A Requirement: The Efficacy and Importance of β-Carotene in Animal Species

Abstract EN

Vitamin A is essential for life in all vertebrate animals.

Vitamin A requirement can be met from dietary preformed vitamin A or provitamin A carotenoids, the most important of which is β-carotene.

The metabolism of β-carotene, including its intestinal absorption, accumulation in tissues, and conversion to vitamin A, varies widely across animal species and determines the role that β-carotene plays in meeting vitamin A requirement.

This review begins with a brief discussion of vitamin A, with an emphasis on species differences in metabolism.

A more detailed discussion of β-carotene follows, with a focus on factors impacting bioavailability and its conversion to vitamin A.

Finally, the literature on how animals utilize β-carotene is reviewed individually for several species and classes of animals.

We conclude that β-carotene conversion to vitamin A is variable and dependent on a number of factors, which are important to consider in the formulation and assessment of diets.

Omnivores and herbivores are more efficient at converting β-carotene to vitamin A than carnivores.

Absorption and accumulation of β-carotene in tissues vary with species and are poorly understood.

More comparative and mechanistic studies are required in this area to improve the understanding of β-carotene metabolism.