Control of vitamin A deficiency in Vietnam: achievements and future orientation.

Vitamin A deficiency is one of the major nutritional deficiencies in Vietnam. The first survey, conducted in 1985-1988 showed that the prevalence of severe xerophthalmia was seven times higher than the cutoff point established by the World Health Organization (WHO) to define vitamin A deficiency as a public health problem. The result of this survey strongly convinced the government to launch a program to control vitamin A deficiency, which started in 1988.