To provide current global and regional estimates of anaemia prevalence and number
of persons affected in the total population and by population subgroup.
We used anaemia prevalence data from the WHO Vitamin and Mineral Nutrition Information
System for 1993-2005 to generate anaemia prevalence estimates for countries with data
representative at the national level or at the first administrative level that is
below the national level. For countries without eligible data, we employed regression-based
estimates, which used the UN Human Development Index (HDI) and other health indicators.
We combined country estimates, weighted by their population, to estimate anaemia prevalence
at the global level, by UN Regions and by category of human development.
Survey data covered 48.8 % of the global population, 76.1 % of preschool-aged children,
69.0 % of pregnant women and 73.5 % of non-pregnant women. The estimated global anaemia
prevalence is 24.8 % (95 % CI 22.9, 26.7 %), affecting 1.62 billion people (95 % CI
1.50, 1.74 billion). Estimated anaemia prevalence is 47.4 % (95 % CI 45.7, 49.1 %)
in preschool-aged children, 41.8 % (95 % CI 39.9, 43.8 %) in pregnant women and 30.2
% (95 % CI 28.7, 31.6 %) in non-pregnant women. In numbers, 293 million (95 % CI 282,
303 million) preschool-aged children, 56 million (95 % CI 54, 59 million) pregnant
women and 468 million (95 % CI 446, 491 million) non-pregnant women are affected.
Anaemia affects one-quarter of the world's population and is concentrated in preschool-aged
children and women, making it a global public health problem. Data on relative contributions
of causal factors are lacking, however, which makes it difficult to effectively address
the problem.