Supplementation with algae such as spirulina and chlorella might improve iron deficiency, though most research is in rats.[1][2][3] One human trial showed that spirulina-containing flour benefitted the iron status and survival rates of infants (aged 6-24 months) when compared to flours without iron. However, the study participants were malnourished infants in Kenya who were hospitalized, decreasing applicability of results to other populations.[4]
Iron supplements will often include vitamin B12 and folate, since iron deficiency can mask symptoms of a deficiency of either of these vitamins. Vitamin B12 and/or folate deficiency can cause a dysfunction of RBCs known as macrocytic anemia (where RBCs are enlarged), but this can be masked by iron deficiency (which would typically make RBCs smaller).
It has been shown that individuals with iron deficiency anemia have higher levels of oxidative stress and lower levels of endogenous antioxidants. Therefore, supplementing with antioxidant vitamins (e.g., vitamin C, vitamin E, and beta-carotene) may be considered in iron deficiency anemia.[5]