Iron deficiency occurs frequently in patients with pernicious anemia.

We assessed iron status in patients with pernicious anemia. Iron deficiency coexisted as a presenting finding in 25 (20.7%) of 121 patients for whom data could be evaluated. Another 27 patients (22.3%) developed iron deficiency one month to 14 years later (median, two years). It was impossible to predict such a development in these 27 patients from any of their initial findings. The cause of the iron deficiency was identified in 17 of the 52 iron-deficient patients and suspected in another four. These findings show that patients with pernicious anemia are at high risk for iron deficiency, both at initial presentation and subsequently. Although the cause of the iron deficiency is often not identifiable, clinically important entities are detected often enough to warrant routine investigation for iron deficiency in such patients.