Is Ferritin 15 ng/mL Normal?
Technically yes, but functionally no. Ferritin 15 is within many labs' "normal" ranges for women (MedlinePlus lists 13–150) but sits at the low end.1 More importantly, 15 is right at the WHO cut-off for iron deficiency and below the 30 ng/mL that marks low iron stores, so your stores are likely depleted.23 You may experience symptoms like fatigue, cold hands/feet, hair loss, or weak nails.456 This needs intervention.
Where Does 15 ng/mL Fall?
| Category | Ferritin Range (ng/mL) |
|---|---|
| Deficient (depleted stores) | <15 |
| Your value (15) | Low-normal; depleted stores |
| Adequate | 30–50 |
| Often called "optimal" (no guideline target) | 50–100 |
| High (investigate cause) | >150 (women), >200 (men) |
The deficiency and overload lines come from the WHO's 2020 ferritin guideline; 30 ng/mL is the level below which UK gastroenterology guidelines consider iron stores low.23
What Ferritin Tells You
Ferritin reflects the iron stored in your body. Iron is essential for hemoglobin (oxygen transport), myoglobin (muscle function), and many enzymes.27 When ferritin drops below 30, your stores are low — even if hemoglobin and iron saturation still look "normal."3 You're in an early stage of iron deficiency before anemia develops.4
Why 15 Feels Bad (Symptoms You Might Have)
Even though your hemoglobin may be normal, at ferritin 15 you may experience:
- Fatigue: A hallmark symptom; in a trial of non-anemic women with ferritin below 50, iron reduced fatigue more than placebo. Even walking or climbing stairs can feel exhausting.48
- Cold extremities: Cold hands and feet are a recognized symptom of iron-deficiency anemia, which impairs body-temperature regulation.59
- Hair loss or thinning: Iron deficiency has been linked to shedding, though studies disagree on whether it causes it.10
- Brittle nails: Brittle nails, and sometimes "spoon nails" (flattened, concave), are signs of iron-deficiency anemia.611
- Difficulty concentrating ("brain fog"): Iron deficiency impairs brain myelination and the metabolism of neurotransmitters such as dopamine.412
- Shortness of breath: Even light exertion can leave you winded.4
- Restless legs: Uncomfortable sensations in legs, especially at night.4
- Sore or swollen tongue: The tongue can become sore or inflamed.6
If you have several of these, low iron is a likely contributor — though fatigue and most of these symptoms have other causes too.
Why You're Here (Common Causes)
Women of reproductive age: Menstrual bleeding is the #1 cause.2 Heavy or prolonged periods deplete iron steadily. If your ferritin is low and you menstruate, discuss menstrual management with your gynecologist.
Vegetarians/vegans: Plant-based iron (non-heme iron) is absorbed less well than heme iron from meat, especially without vitamin C. You need higher dietary intake — about 1.8 times the usual recommendation.13
Digestive disorders: Celiac disease, Crohn's disease, and H. pylori infection reduce iron absorption.314
Older age: Conditions that lower stomach acid, such as atrophic gastritis, reduce iron absorption from food.37
Frequent blood donation: Each donation removes iron-rich blood.15
Medications: PPIs and H2 blockers reduce stomach acid, worsening iron absorption.16
Poor diet: Insufficient red meat, poultry, fish, beans, or fortified grains.4
What to Do Next
1. Confirm iron-deficiency anemia status: Ask your doctor to also check:
- Hemoglobin (is it normal or low?)
- Iron saturation (is it low?)
- TIBC (total iron-binding capacity)
- Complete blood count (CBC)
If hemoglobin is normal but ferritin is low, you have iron-deficiency without anemia (IDWA) — catch it now before anemia develops.17
2. Start iron supplementation:
- Ferrous sulfate, one tablet (65 mg elemental iron) daily or every other day, is standard.34 Take it on an empty stomach if tolerated, since food can cut absorption by up to 75%; take with food if it causes nausea. Adding orange juice or vitamin C hasn't been shown to improve results with iron tablets.318
- Or try iron bisglycinate: Better tolerated, with fewer GI side effects in trials (mostly in pregnant women) and hemoglobin gains at least as good.19
- Avoid calcium, coffee, tea, and dairy within 2 hours of iron — they inhibit absorption.2021
3. Increase dietary iron:
- Heme iron (best absorbed): Red meat, poultry, fish.13 Aim for 3–4 servings weekly.
- Non-heme iron: Beans, lentils, fortified cereals, dark leafy greens. Pair with vitamin C (citrus, peppers, tomatoes) to boost absorption.13
4. Check for underlying causes:
- Women: Track your menstrual flow. If heavy or prolonged, see a gynecologist about management (IUD, hormonal birth control, or medical treatment).22
- Everyone: Ask about celiac disease, H. pylori, or other absorption issues if dietary iron and supplements don't work.23
5. Retest ferritin in 8–12 weeks:
- Ferritin rises gradually: in a 12-week trial of 80 mg a day in non-anemic women, it rose about 11 ng/mL more than with placebo.8
- Goal: at least back above 30 ng/mL, the line for low stores.3
- If ferritin doesn't rise with supplementation, suspect malabsorption and investigate further.3
6. Maintain iron levels:
- Once ferritin has recovered, continue dietary iron or lower-dose supplementation (10–25 mg daily) to sustain it.
- Retest annually to monitor.
When to Escalate
Contact your doctor if:
- You develop chest pain, severe shortness of breath, or heart palpitations (signs of severe anemia).56
- Ferritin doesn't rise after 8 weeks of supplementation (possible malabsorption).
- You also have joint pain, heart problems, or family history of iron overload (hemochromatosis risk).24
How Merios Helps
Merios tracks your ferritin trend and tells you whether supplementation is working. We flag low ferritin and its associated symptoms, remind you to retest, and show you progress over months. You'll see at a glance whether your iron stores are recovering or remaining depleted.
Upload your blood test to Merios →
Related: Oral iron supplements not working? · Low ferritin, normal hemoglobin · Ferritin 30 (low-normal)
Medical Disclaimer
This article is for educational purposes only and is not a substitute for professional medical advice. Always consult your doctor before starting iron supplementation, as excessive iron can be harmful. Do not take iron supplements without medical guidance, especially if you have hemochromatosis, chronic liver disease, or other iron metabolism disorders.