Vitamin and Mineral Nutrition Information System (VMNIS)

Global prevalence of vitamin A deficiency in population at risk: 1995-2005

Summary of the global prevalence of vitamin A deficiency in populations at risk

In 1987, WHO estimated that vitamin A deficiency was endemic in 39 countries based on the ocular manifestations of xerophthalmia or deficient serum (plasma) retinol concentrations (<0.35 µmol/l).="" in="" 1995,="" who="" updated="" these="" estimates="" and="" reported="" that="" vitamin="" a="" deficiency="" was="" of="" public="" health="" significance="" in="" 60="" countries,="" and="" was="" likely="" to="" be="" a="" problem="" in="" an="" additional="" 13="" countries.="" the="" current="" estimates="" reflect="" the="" time="" period="" between="" 1995="" and="" 2005,="" and="" indicate="" that="" 45="" and="" 122="" countries="" have="" vitamin="" a="" deficiency="" of="" public="" health="" significance="" based="" on="" the="" prevalence="" of="" night="" blindness="" and="" biochemical="" vitamin="" a="" deficiency="" (serum="" retinol="" concentration=""><0.70 µmol/l),="" respectively,="" in="" preschool-age="" children.="">

In this present edition, estimates of vitamin A deficiency are provided for preschool-age children as in the previous edition, and also for pregnant women. They are based on an increasingly assessed history of night blindness and a now more widely adopted serum (plasma) retinol concentration, using a cut-off of <0.70 µmol/l=""><20 µg/dl)="" to="" define="" deficiency.="">

Globally, night blindness is estimated to affect 5.2 million preschool-age children (95% CI: 2.0-8.4 million) and 9.8 million pregnant women (95% CI: 8.7-10.8 million), which corresponds to 0.9% and 7.8% of the population at risk of VAD, respectively. Low serum retinol concentration (<0.70 µmol/l)="" affects="" an="" estimated="" 190="" million="" preschool-age="" children="" (95%="" ci:="" 178-202="" million)="" and="" 19.1="" million="" pregnant="" women="" (95%="" ci:="" 9.30-29.0="" million)="" globally.="" this="" corresponds="" to="" 33.3%="" of="" the="" preschool-age="" population="" and="" 15.3%="" of="" pregnant="" women="" in="" populations="" at="" risk="" of="" vad,="" globally.="" the="" who="" regions="" of="" africa="" and="" south-east="" asia="" were="" found="" to="" be="" the="" most="" affected="" by="" vitamin="" a="" deficiency="" for="" both="" population="" groups.="">

Despite a marked increase in submitted data, there are still numerous countries lacking national prevalence data. There is a need to inform and motivate governments and agencies to collect, and report to WHO, national data on the prevalence of deficiency and, whenever possible, vitamin A programme coverage conditions prevailing at the time that population assessment data were collected.

We hope that readers will find this report useful and feel free to share any comments with us ( We also hope that this information will contribute to our common goal to eliminate vitamin A deficiency as a public health problem.

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