title: Dietary carotenoids and their role in combating vitamin A deficiency: a review of the literature.
abstract: OBJECTIVE
  To evaluate the evidence that carotene-rich fruits and vegetables can overcome vitamin A deficiency.
  
  
  METHODS
  Results of studies on the relationship between dietary carotenoids and vitamin A deficiency were evaluated critically.
  
  
  RESULTS
  Increased intake of fruits and vegetables has been shown to be related to improved vitamin A status in many cross-sectional, case-control and community-based studies, but this does not prove causality of the relationship. Many experimental studies indicating a positive effect of fruits and vegetables can be criticized for their poor experimental design while recent experimental studies have found no effect of vegetables on vitamin A status. Thus, it is too early to draw firm conclusions about the role of carotene-rich fruits and vegetables in overcoming vitamin A deficiency. Bioavailability of dietary carotenoids and their conversion to retinol are influenced by the following factors: Species of carotene; molecular Linkage; Amount of carotene in a meal; Matrix in which the carotenoid is incorporated; Absorption modifiers; Nutrient status of the host; Genetic factors; Host-related factors and Interactions (SLAMANGHI). Studies are required to quantify the impact of these factors, especially of the matrix, host-related factors and absorption modifiers.
  
  
  CONCLUSIONS
  The effectiveness of carotene-rich foods in improving vitamin A status and ways of improving carotene bioavailability need further investigation.
authors.affiliation: Department of Human Nutrition, Wageningen Agricultural University, Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: de Pee
authors.forename: C E
authors.initials: CE
authors.lastname: West
mesh_terms: D001682:Biological Availability; D002338:Carotenoids / Q000008:administration & dosage* / Q000502:physiology / Q000627:therapeutic use; D004032:Diet; D005638:Fruit; D006801:Humans; D007214:Indonesia; D014675:Vegetables; D014802:Vitamin A Deficiency / Q000188:drug therapy / Q000517:prevention & control*
chemical_list: D002338:Carotenoids