September 6, 1985

Improved Detection of Early Iron Deficiency

Author Affiliations

The Lutheran Home Topton and Allentown, Pa
Medical College of Ohio Toledo

JAMA. 1985;254(9):1174. doi:10.1001/jama.1985.03360090064014

To the Editor.—  In a recent article in The Journal, McClure et al1 reported an improved method—red blood cell distribution width—for the detection of early iron deficiency in nonanemic subjects; however, their methodology for determining iron deficiency, namely, serum transferrin saturation, and their statement that reduced iron saturation equates with chemical evidence of iron deficiency must be challenged.The gold standard for the diagnosis of iron deficiency is the absence of stainable iron stores in the bone marrow. An acceptable and more easily attainable alternative method is measurement of the serum ferritin level. A serum ferritin level less than 12 μg/L is diagnostic of iron deficiency.2 Normal serum ferritin levels in the presence of deficient bone marrow iron stores have been reported in rheumatoid arthritis, hepatic disease, leukemia, lymphoma, and active inflammatory bowel disease; however, exclusion of these diseases is relatively simple and, thus, the serum ferritin level