Table 1.

The criteria for a population, intervention/exposure, comparator, outcome, and study design (PICOS).

PICOS	Inclusion Criteria	Exclusion Criteria
Population	Anemic and non-anemic pregnant women	Pregnant women with diseases and conditions, which may influence either iron status or reliability of results
Intervention/exposure	Dietary intervention applied to prevent or treat anemia	Undefined dietary intervention
Comparison	Effectiveness of dietary intervention vs. effectiveness of supplementation/placebo/control, or the other dietary approach	Effectiveness of dietary intervention not defined, or influenced by interfering factors
Outcome	Biochemical parameters of anemia/iron stores/iron status	Biochemical parameters of anemia/iron stores/iron status for a mixed population of pregnant and non-pregnant women
Study design	Randomized controlled trials	Results not published peer-reviewed journals, not published in English, and retracted articles