Specialty Testing Guide › TruHealth Micronutrient Testing
Iron is one nutrient where both too little and too much cause real harm. Iron deficiency is one of the leading nutrition problems worldwide and can sap your energy well before it causes anemia.1 Iron overload, most often from the inherited condition hemochromatosis, can quietly damage the liver, heart, joints and pancreas over many years.
Because the risks run in both directions, iron is the one supplement you should not start on a hunch. A simple blood test tells you which side of the line you are on.
Key takeaways
- Ferritin reflects iron stores, but inflammation, liver disease and heavy drinking can push it up even when stores are low or normal.
- Low iron in a man or a woman past menopause usually means hidden blood loss until proven otherwise.
- Hemochromatosis is common in people of northern European ancestry and is treated by removing blood, not with diet alone.
- Iron pills belong only in a plan based on test results, and they must be kept away from children.
What ferritin tells you
Ferritin is a protein that stores iron, and the amount in your blood roughly tracks how much iron you have in reserve. A low ferritin is the most reliable single sign of iron deficiency.
A high or normal ferritin is harder to read. Ferritin also rises with inflammation, infection, fatty liver disease and alcohol use, so a "normal" number can hide low stores in someone with an inflammatory condition. For that reason clinicians usually read ferritin together with a complete blood count, serum iron, total iron-binding capacity and transferrin saturation, which is the share of the iron-carrying protein in your blood that is actually loaded with iron.
Iron deficiency: who gets it and why
Iron deficiency usually comes from losing more iron than you take in. Common causes include:
- Heavy menstrual periods and pregnancy
- Bleeding from the stomach or bowel, often unnoticed
- Frequent blood donation
- Diets low in meat, fish and poultry, especially without iron-rich plant foods
- Poor absorption from celiac disease, weight-loss surgery or long-term acid-reducing medicine
In a CDC national survey, roughly 1 in 10 women aged 12 to 49 was at risk of iron deficiency.2 Symptoms include tiredness, shortness of breath with activity, pale skin, headaches, restless legs and craving ice. Low iron can affect how you feel and function even before your blood count shows anemia.
Finding the cause matters as much as replacing the iron. An underlying cause should be sought in everyone with iron deficiency, screening for celiac disease should be considered routinely, and men and postmenopausal women with iron deficiency anemia need an evaluation of the digestive tract.1 Our guide to gut absorption and nutrient levels explains the absorption side in more detail.
Iron overload and hemochromatosis
Hereditary hemochromatosis is one of the most common genetic disorders in people of northern European descent.3 Most cases come from inheriting two copies of a change in the HFE gene called C282Y, which makes the gut absorb more iron than the body needs.
Early overload often causes no symptoms. Over time it can cause fatigue, joint pain (often in the knuckles), abdominal pain, diabetes, low sex drive, darkened skin, liver scarring and heart rhythm problems. Signs that suggest it include a high transferrin saturation and a high ferritin, with genetic testing to confirm.
Not every high ferritin means hemochromatosis. In people who do not carry two copies of C282Y, fatty liver disease and alcohol-related liver disease are more common causes of a high ferritin than hemochromatosis.3 Removing blood on a schedule, called phlebotomy, remains the main treatment for confirmed hemochromatosis.
Why you should never take iron without a test
Iron supplements can help a great deal when you are truly low, but they carry real risks when you are not:
- In someone with undiagnosed hemochromatosis, extra iron speeds up organ damage.
- Taking iron for vague fatigue can delay the search for bleeding, including from the colon.
- Iron pills often cause constipation, nausea and stomach upset.
- Iron is dangerous to small children. US labels on iron-containing supplements must warn that accidental overdose is a leading cause of fatal poisoning in children under 6.4
If a child swallows iron pills, call Poison Control at 1-800-222-1222 right away. Many multivitamins contain iron too, so check labels before you combine products.
How testing works in practice
For most people, the first tests are a complete blood count and iron studies, ordered by a primary care clinician and drawn at a local lab anywhere in Pennsylvania. Those tests answer the key question directly.
Specialty panels add a different kind of information. TruHealth, from TruDiagnostic, estimates nutrient-related markers from DNA methylation patterns rather than measuring iron or ferritin in your blood.5 Whatever such a panel suggests, iron decisions should rest on standard iron studies, because the cost of getting it wrong runs in both directions. For how these symptoms overlap with other nutrients, see the signs of nutrient deficiency.
Your next step
If you are thinking about supplements after any kind of nutrient test, read supplement safety after testing, which covers iron and other nutrients where more is not better. The micronutrient testing hub has the rest of the series.
Frequently asked questions
Can I have low iron without anemia?
Yes. Iron stores run down before hemoglobin falls, so ferritin can be low while your blood count is still normal. Some people feel tired or short of breath at this stage.
Should I be tested for hemochromatosis?
Testing makes sense if you have a high transferrin saturation or ferritin, unexplained liver problems, or a parent, sibling or child with hemochromatosis. Ask your clinician whether iron studies, and then genetic testing, fit your situation.
Does cooking in cast iron or eating red meat cause overload?
In people without hemochromatosis, normal diets rarely cause iron overload because the gut limits how much it absorbs. People with hemochromatosis are usually advised to avoid iron supplements and vitamin C supplements with meals, and to discuss diet with their clinician.
Related reading
This article is for general education and is not medical advice. Decisions about testing and treatment should be made with your clinician. If you have severe symptoms, call 911. For a suspected poisoning, call Poison Control at 1-800-222-1222.
