Globally, it is estimated that 140–250 million children under five years of age are affected by vitamin A deficiency. These children suffer a dramatically increased risk of death, blindness and illness, especially from measles and diarrhoea. As part of the global call to action, the UN Special Session on Children in 2002 set the goal of the elimination of vitamin A deficiency and its consequences by the year 2010. The fourth Millennium Development Goal is to reduce by two thirds the mortality rate among children under five year of age by 2015. Vitamin A supplementation (VAS) is an important component of the strategies required to reach this goal.
Provision of vitamin A supplements every four to six months is an inexpensive, quick, and effective way to improve vitamin A status and save children's lives. Comprehensive control of vitamin A deficiency must include dietary improvement and food fortification in the long term. In areas where vitamin A deficiency is a public health problem, improving the vitamin A status of deficient children aged 6-59 months significantly increases their chances of survival.
Combining the administration of vitamin A supplements with immunization services is an important part of the effort to eliminate vitamin A deficiency and save lives. WHO advocates the routine administration of vitamin A with vaccination in countries where vitamin A deficiency is a public health problem. Millions of children have received vitamin A through National Immunization Days (NIDs) to eradicate poliomyelitis. Vitamin A supplementation has been successfully linked with vaccination campaigns and routine immunization services in many countries. Providing high-dose supplementation to mothers at immunization contacts soon after delivery provides a further benefit to young infants through enriched breast milk.