We reviewed the recent assertion that population strategies of prevention may inadvertently widen social inequalities in health. We used folate intake as a case example to examine what is known about the impact on inequalities of 2 population strategies: one agentic (public information campaign) and the other structural (mandatory fortification policy). We found some support for our hypothesis that the mandatory fortification policy was less likely than were the information campaigns to lead to worsening inequalities in health by socioeconomic status or race/ethnicity; however, conclusions were complicated by different outcome variables and different economic and political regimes in which interventions took place