Pro-vitamin A Carotenoids: Aspects of the Biology, Chemical Analysis, and Utilization of Foods for Improving Public Health

Vitamin A deficiency continues to be a public health problem in many countries. Several carotenoids, such as alpha- and beta-carotene and beta-cryptoxanthin found in plants, are capable of forming vitamin A in humans. Pro-vitamin A carotenoid-rich foods are an important and often sole source of vitamin A in many areas of endemic deficiency. Thus, understanding the biological conditions, which types of foods are the most efficacious in providing vitamin A, and the feasibility of these foods to prevent and reduce vitamin A deficiency in humans is critical. Presented first is a review of the literature on the chemistry and potential health benefits of beta-cryptoxanthin, a carotenoid that has not been well studied for its vitamin A potential. Then an examination of the feasibility and effectiveness of using carotenoid-rich foods to provide vitamin A at the individual level and on a global scale is provided. Subsequently, the development and validation of an improved HPLC method is described as well as extraction techniques to efficiently and accurately measure carotenoids and vitamin A in biologicals. Finally, a randomized clinical trial using carotenoid-rich foods as a vitamin A intervention in lactating, vitamin A-deficient women in Bangladesh is discussed. Collectively this research supports the use of pro-vitamin A-rich foods to improve health and reduce and treat vitamin A deficiencies; it also provides evidence of the potential feasibility of using several foods rich in carotenoids to provide vitamin A on a large scale. The continued research into the metabolism and bioefficacy of beta-cryptoxanthin and other pro-vitamin A carotenoids to provide vitamin A in humans is recommended, and investigation into the translation of this science into public health interventions are warranted.