Defining iron-deficiency anemia in public health terms: a time for reflection.

This paper provides a historical context for this meeting, which aimed to examine critically the way we have defined iron-deficiency anemia as a public health problem. The terms and concepts used to define the problem are reviewed first, followed by estimates of the global prevalence of the problem from 1985 to 2000. It is argued that recent estimates are not credible and that we must redefine the problem in terms that are important, measurable and addressable. This meeting was designed to take first steps toward that goal, namely, to identify the causal factors (e.g., iron deficiency vs. iron-deficiency anemia vs. severe anemia from any cause) that link iron-deficiency anemia to important health outcomes and to estimate the magnitude of their effects in public health terms.