“…Other aspects should be taken into account, too: 1) the biological plausibility of the observed association is a meaningful relationship; 2) regarding the biological gradient of the observed association, there is a relationship between the extremes (> poverty and < educational level = > risk of anemia); and 3) the consistency of our research findings with which is known about the natural history of the disease. In fact, poverty produces not only direct effects but also non financial costs, such as hunger, undernourishment and malnutrition, which contribute to arise feelings of deprivation and frustration, apart from pain, suffering and reduced life quality [4] .…”