ABSTRACT
Vitamin A deciency (VAD) is a signicant public health concern in the developing world, especially in Africa and Southeast Asia. Estimates from the World Health Organization between 1995 and 2005 identied VAD to be affecting 190 million
Introduction ............................................................................................................ 319 Background on Vitamin A Deciency ................................................................... 320
Effects of VAD .................................................................................................. 320 Current Statistics on Vitamin A Deciency ...................................................... 320 Historical Data on VAD Coverage and Development of Programs .................. 321
Sources of Vitamin A in Developing Countries ..................................................... 325 Provitamin A Carotenoid Sources ..................................................................... 325 Preformed Vitamin A......................................................................................... 327 Food Fortication and Biofortication ............................................................. 327
Fortied Items and Effectiveness ................................................................. 328 Acceptance and Effects ................................................................................ 329 Biofortication Constraints .......................................................................... 330 Home Fortication ....................................................................................... 330 Multiple Micronutrient Fortication and Safety .......................................... 330 Agriculture/Horticulture/Farm-Based Approach for Food Diversication; Biofortication Adoption .................................................... 331
Roles of Vitamin A during Particular Times in the Life Cycle: Maternity, Pregnancy, Lactation, Neonatal Period, Infancy, and Childhood........................... 334
Increased Bodily Needs..................................................................................... 334 Importance of Breast Milk ................................................................................ 334 Effects on Pregnant and Lactating Women ....................................................... 334 Evidence for Supplementation in Neonates, Infants, and Children under 5 Years ............................................................................................................... 335 Future Directions ............................................................................................... 335 Differential Effect between Africa and Asia ..................................................... 336
Conclusion ............................................................................................................. 336 References .............................................................................................................. 338
school children (∼32%) and nearly 20 million pregnant women (∼10%).1 Causes for VAD include poverty, infections, and lack of access to traditional foods containing vitamin A.2 Vitamin A sources in developing countries are primarily consumed in the form of provitamin A carotenoids from plant sources, with animal-derived preformed vitamin A (retinol) comprising little of the daily vitamin A intake.3 The vitamin plays essential roles in human physiology for normal functioning of the immune system, visual system, and maintenance of cell function for growth, bone development, red blood cell production, and reproduction.4 Long-term deciency can cause night blindness and xerophthalmia and is a major contributor to mortality in developing countries. Regular delivery of vitamin A doses have proved effective in reducing child mortality by as much as 24% on average.5 In addition to supplementation programs, other types of interventions used to improve vitamin A status of populations include dietary diversication, fortication of common food staples, and biofortication.6
