Stephanie Weinberg Levin, MD Clinical Instructor Assistant Program Director, Adult Residency Program Department of Psychiatry University of Michigan Ann Arbor, Michigan
Theresa B. Gattari, MD House Officer IV Department of Psychiatry University of Michigan Ann Arbor, Michigan
Disclosures The authors report no financial relationships with any companies whose products are mentioned in this article, or with manufacturers of competing products.
Individuals with iron deficiency without anemia also may see improvement in psychiatric symptoms with iron treatment. In a 2018 systematic review, Houston et al20 evaluated iron supplementation in 1,170 adults who were iron-deficient but not anemic. They found that in these patients, fatigue significantly improved but physical capacity did not.20 Additionally, 2 other studies found iron treatment improved fatigue in nonanemic women.21,22 In a 2016 systematic review, Pratt et al23 concluded, “There is emerging evidence that … nonanemic iron deficiency … is a disease in its own right, deserving of further research in the development of strategies for detection and treatment.” Al-Naseem et al24 suggested severity distinguishes iron deficiency with and without anemia.
Your role in assessing and treating iron deficiency
Testing for and treating iron deficiency generally is not a part of routine psychiatric practice. This might be due to apathy given the pervasiveness of iron deficiency, a belief that iron deficiency should be managed by primary care physicians, or a lack of familiarity with how to treat it and the benefits of such treatment for psychiatric patients. However, assessing for and treating iron deficiency in psychiatric patients is important, especially for individuals who are highly susceptible to inadequate iron levels. People at risk for iron deficiency include pregnant women, infants, young children, women with heavy menstrual bleeding, frequent blood donors, patients with cancer, individuals who have gastrointestinal (GI) surgeries or disorders, and those with heart failure.25
Assessment. Iron status can be assessed through an iron studies panel. Because a patient can have iron deficiency without anemia, a complete blood count (CBC) alone does not suffice.26 The iron panel includes serum iron, serum ferritin, serum transferrin or total iron-binding capacity (TIBC), and calculated transferrin saturation (TSAT), which is the ratio of serum iron to TIBC.
Iron deficiency is diagnosed if ferritin is <30 ng/mL, regardless of the hemoglobin concentration or underlying condition, and confirmed by a low TSAT.26 In most guidelines, the cutoff value for TSAT for iron deficiency is <20%. Because the TSAT can be influenced by iron supplements or iron-rich foods, wait several hours to obtain blood after a patient takes an oral iron supplement or eats iron-rich foods. If desired, clinicians can use either ferritin or TSAT alone to diagnose iron deficiency. However, because ferritin can be falsely normal in inflammatory conditions such as obesity and infection, a TSAT may be needed to confirm iron deficiency if there is a high clinical suspicion despite a normal ferritin level.26
Treatment. If iron deficiency is confirmed, instruct your patient to follow up with their primary care physician or the appropriate specialist to evaluate for any underlying etiologies.
