Health & Medications

Iron-Deficiency Guidelines Put More Weight on Ferritin and Patient Context

By Lena Ortiz / October 24, 2026 / Updated November 8, 2026

Patient reviewing a medical chart with a healthcare professional

The American Society of Hematology (ASH), a large professional society of blood specialists, has published new guidelines on how to diagnose iron deficiency. The main change is that doctors are now advised to use higher cut-off numbers on a blood test called serum ferritin, and to read the result in light of the person’s age, health and circumstances. Some people whose results were once called normal may now fall into the “low iron” range. That is a reason to have a conversation with a doctor, not a reason to start taking iron on your own.

Key takeaways

ASH announced its diagnostic guidelines on 16 September 2026, and they appear in the journal Blood Advances. They cover diagnosis only. ASH says guidance on treatment is expected in 2027.
For most adults, the suggested ferritin cut-off is now 30 ng/mL or lower, up from 15. For some people with symptoms or ongoing risk factors it is 50.
For people with inflammation, ferritin alone can mislead, so a second test is suggested.
The recommendations rest on low-certainty or very-low-certainty evidence, and the authors call for more research.
The guideline says its thresholds are not automatic triggers for iron supplements.

What ASH published, and what has happened since

The document is ASH’s 2026 clinical practice guidelines for the diagnosis of iron deficiency. Jacquelyn Powers chaired the panel. ASH issued a press release on 16 September 2026. On 23 October 2026, JAMA ran a short report on it, and Healio, in October, quoted a guideline co-author, Dr. Angela Weyand. The evidence review behind the guideline ran through July 2025.

As of 8 November 2026, ASH’s guideline page lists the diagnosis guideline as new and the treatment guideline as “under development.” ASH’s announcement says additional treatment guidance is expected in 2027. We could not confirm the status of any draft treatment recommendations, so we do not describe them here.

Some terms, explained once:

Iron deficiency means the body’s iron stores are low. Iron deficiency anemia is the later stage, when low iron has also reduced the red blood cells that carry oxygen.
Ferritin is the protein that stores iron. A blood test measures it in nanograms per milliliter (ng/mL). A lower number suggests lower iron stores.
Transferrin saturation (TSAT) is a second blood test, showing how much of the iron-carrying protein is loaded with iron.

ASH says an estimated 2 billion people worldwide, and about 10 million U.S. adults, have iron deficiency. It reports that up to 70% of cases may be missed in higher-risk groups, partly because screening is limited and laboratories use different reference ranges.

The new ferritin thresholds

The table follows the guideline as summarized by ASH and by News-Medical. The right row for any person depends on their circumstances.

Group	Suggested ferritin cut-off (ng/mL)	Notes
Children aged 9 months to 4 years, no known inflammation	20 or lower	Previously 12
Adults who are not menstruating or pregnant	30 or lower	Previously 15. Up to 50 if there are signs, symptoms or ongoing risk factors
Menstruating individuals	30 or lower	Previously 15. Up to 50 with heavy bleeding, symptoms, upcoming surgery or plans for pregnancy
Pregnancy	30 or lower	The panel advises against 15. Up to 50 if anemia is present
Adults with inflammation (for example cancer, inflammatory bowel disease or infection)	Below 100, or TSAT below 20%	Either result is enough; both are not required

Most of the ferritin cut-offs apply to people with no known or suspected inflammation. The guideline applies whether or not a person has anemia, which matters because iron can run low before blood counts change. Healio’s report adds that a standard blood count often misses iron deficiency, so ferritin may need to be requested as a separate test.

JAMA’s report describes the cut-offs as raised, with adult values going from 15 to 30 and children’s from 12 to 20. ASH notes that people whose results were close to the old cut-off, and who were previously judged not deficient, may now meet the criteria.

Why one number is never the whole story

Ferritin is useful, but imperfect. The guideline summary points out several reasons to read it with care.

Inflammation raises ferritin. A normal or even high result does not rule out low iron in someone with an inflammatory condition. That is why adults with inflammation have a separate rule, using ferritin and TSAT together.
Labs differ. Different laboratory methods can give different results for the same sample, especially at higher values.
TSAT needs preparation. The guideline suggests TSAT be measured after roughly 5 to 9 hours of fasting, without iron or multivitamin supplements in that time.
Ferritin is not the full picture. Dr. Weyand acknowledged that ferritin says little about how well iron reaches tissues such as muscle and brain.

The evidence is also modest. According to News-Medical’s summary of the paper, the first four recommendations rest on low-certainty evidence. The pregnancy recommendation and the recommendation for people with inflammation are conditional, and the latter rests on very-low-certainty evidence. Healio reports that the authors would have liked firmer evidence for using 50 across all higher-risk groups, and that research on this topic has been underfunded. In plain words, the new numbers are the panel’s best judgment from limited research.

What the guideline does not do

The limits are easy to miss in headlines.

It is about diagnosis, not treatment. How to treat iron deficiency, including whether to use pills or infusions, is the subject of separate guidance expected in 2027.
It is not a screening guideline. It does not judge who should be tested. Other guidelines cover that.
It does not say to give iron automatically. The authors state that the thresholds guide clinical assessment, and that treatment depends on the cause, the person’s condition, and risks and benefits.
It is not the standard of care. It is guidance that doctors and health systems may adopt.

Healio’s report adds a point worth noting: finding and treating the cause of low iron matters, not only correcting the number, to avoid repeated treatments. Your doctor decides what a low result means in your case.

A checklist for talking with your doctor

This list is a way to prepare, not medical advice.

Bring the date and value of any earlier ferritin result, and the reference range printed on that laboratory report.
Write down any symptoms and when they started.
List every medicine and supplement I take, including any iron or multivitamins.
Mention any long-term conditions, especially bowel disease, inflammation or past bleeding.
Ask whether the new guideline changes how my earlier results should be read.
Ask whether ferritin, and possibly TSAT, should be repeated, and how to prepare.
Ask what could cause low iron if it is found, and how that would be checked.

Frequently asked questions

My ferritin was called normal before. Does that now mean I am iron deficient?

Not automatically. ASH notes that people close to the old cut-off may now meet the new criteria, but the cut-off you fall under depends on your circumstances and any inflammation. Ask the doctor who knows your history.

Should I start an iron supplement because of this guideline?

The guideline itself says its thresholds are not automatic triggers for supplements. Please talk to your doctor or pharmacist first, because the cause of low iron matters.

Why does inflammation change the numbers?

Inflammation can push ferritin up even when iron stores are low, so a reassuring ferritin may hide a problem. For adults with inflammation, the guideline says a ferritin below 100, or a TSAT below 20%, can point to iron deficiency.

Will treatment advice change too?

Possibly. ASH says treatment guidance is expected in 2027. Until then, treatment remains a decision between each person and their clinician.

Before you decide

These guidelines are a serious effort to make iron testing more consistent, and they were developed with a patient’s input as well as specialists’. They are also limited by thin evidence, and they say plainly that numbers need context. If you have unexplained symptoms, or an earlier result you were unsure about, the most useful step is a calm conversation with your doctor, with your records in hand. Please do not choose an iron dose from a headline.