American Society of Hematology raises ferritin thresholds for iron deficiency

The American Society of Hematology issued new clinical guidelines on September 16, 2026, establishing higher ferritin thresholds to diagnose iron deficiency at or below 30 nanograms per milliliter for most adults. Published in Blood Advances, the standards replace traditional cutoff levels that experts say have long missed patients suffering from the common blood disorder.

Under the new standards, the diagnostic cutoff for otherwise healthy adults sits at or below 30 ng/mL, while high-risk groups such as women with heavy menstrual bleeding receive a higher threshold of 50 ng/mL. Children aged 9 months to 4 years have a suggested threshold of 20 ng/mL or lower. These population-specific levels sit above the World Health Organization cutoffs of 12 ng/mL in young children and 15 ng/mL in older individuals.

Panel co-chair Jacquelyn M. Powers explained that the guidelines prioritize recognizing individuals with iron deficiency to prevent negative health consequences from missed diagnoses. Pooled global prevalence sits at 30 percent in young children, 27 percent in menstruating individuals, and 37 percent in pregnancy. In the United States, analyses from 2017 to 2020 national surveys using the 30 ng/mL cutoff found absolute iron deficiency in 14 percent of adults and 34 percent of women younger than 50 years.

Higher Thresholds Help Identify Iron Deficiency in Women

Iron deficiency frequently goes unrecognized in girls and younger women who experience symptoms like fatigue or difficulty concentrating. Conditions such as heavy menstrual periods, irritable bowel syndrome, endometriosis, uterine fibroids, gastric bypass, and celiac disease can affect iron levels in women. Powers stated that utilizing a higher threshold of 50 ng/mL for individuals with heavy bleeding helps capture nuances and symptoms before patients progress rapidly to iron deficiency anemia.

Cross-sectional studies show a 15 ng/mL cutoff yields a pooled sensitivity of 0.41 and specificity of 0.99, while raising the threshold to 30 ng/mL increases sensitivity to 0.67 with 0.96 specificity. At 50 ng/mL, sensitivity reaches 0.89 with 0.86 specificity. While lower specificity raised concerns among panel members regarding false positives and unnecessary treatments or bidirectional endoscopy, the standards emphasize individualized clinical evaluation.

Powers noted that automatic flagging of results below the threshold makes it easier for primary care clinicians, generalists, and specialists to act consistently. However, many existing reference ranges derived from healthy populations include iron-deficient individuals, meaning a standard 30 ng/mL reading can fluctuate between 21 and 42 ng/mL depending on the testing laboratory.

Clinicians should also discuss with their patients whether they have symptoms that are associated with iron deficiency, including fatigue or restless legs syndrome, to determine whether iron therapy may be beneficial.

Jacquelyn M. Powers

Evaluating Anemia of Inflammation and Treatment Guidelines Ahead

For adult patients with anemia of inflammation, the panel recommends ordering ferritin and transferrin saturation simultaneously, considering iron deficiency when transferrin saturation falls below 20 percent or ferritin drops below 100 ng/mL. The panel acknowledged that existing evidence is thin and called for randomized clinical trials comparing patient outcomes across different thresholds.

While these diagnostic standards arrived in September 2026, corresponding American Society of Hematology guidance focused specifically on treatment is expected to be released in 2027.