Summary: Implications for research and programs

This paper provides summary judgments about the strength of the evidence th at iron deficiency or anemia causes the six functional outcomes that were r eviewed in the preceding papers, highlights priority research needs and dis cusses the implications of these conclusions for advocacy and programs. A s ignificant body of evidence supports a causal relationship between iron def iciency and deficits in work productivity and child development, and betwee n severe anemia and maternal and child mortality. Causal evidence is lackin g or contradictory for iron deficiency and low birth weight and infectious disease, and for mild-to-moderate anemia and child or maternal mortality. F uture research is required to expand or refine these conclusions. In the me antime, advocacy should focus on the outcomes supported by substantial caus al evidence, These causal relationships can be separated into a problem of severe anemia (which causes mortality) and tissue iron deficiency (which ca uses deficits in work performance and child development). The simple model depicting severe anemia and tissue iron deficiency as distinct but overlapp ing entities with distinct functional outcomes is presented and may be usef ul in designing and evaluating programs.