Depression is a mental disorder that is usually comorbid with physical illnesses, which suggests shared underlying pathophysiological mechanisms (e.g., inflammatory system and brain adaptation). Korkmaz et al. (2015) found that anemia has been more prevalent in patients with psychiatric disorders, including depression, than in those who don’t have any such condition. A more recent study reported the association between anemia and depression has been found more in a non-clinical adult population than in healthy adults (Vulser et al., 2016). Though there are few research on iron deficiency anemia (IDA), the most frequent nutritional deficit, a link between IDA and depression intensity and its relationship to somatic (especially gastrointestinal) symptoms was found in 125 IDA patients compared to 57 healthy controls (Pamuk et al., 2015). Moreover, Murat et al. (2015) reported that IDA had a negative impact on sleep quality, anxiety, and depression in 104 IDA patients compared to 80 healthy controls. In addition, the presence of serum iron deficiency was linked to depressive symptoms in 1875 aged people (Stewart & Hirani, 2012).

.