What are the recommended ferritin levels for women?

Recommended Ferritin Levels for Women

For women, ferritin levels should be maintained above 30 μg/L, with iron deficiency diagnosed when ferritin falls below 30 μg/L, and iron deficiency anemia diagnosed when ferritin is below 45 ng/mL accompanied by low hemoglobin (< 12 g/dL). 1, 2

Normal Ferritin Ranges by Menopausal Status

Premenopausal Women

• Normal range: 30-300 μg/L 1
• Iron deficiency threshold: < 30 μg/L 1
• Diagnostic cutoff for iron deficiency anemia: < 45 ng/mL 2
• Typical median values: 37-42 μg/L 3, 4

Postmenopausal Women

• Normal range: 30-300 μg/L 1
• Iron deficiency threshold: < 30 μg/L 1
• Typical median values: 71-84 μg/L 3, 5

Clinical Interpretation of Ferritin Levels

Low Ferritin (< 30 μg/L)

• Indicates depleted or small iron stores 1
• More common in premenopausal women (35-48% prevalence) than postmenopausal women (13-14% prevalence) 3, 4
• Requires investigation and treatment, particularly when accompanied by anemia

Ferritin 30-45 ng/mL

• May still indicate iron deficiency when accompanied by low hemoglobin 2
• The American Gastroenterological Association recommends using 45 ng/mL as the cutoff for diagnosing iron deficiency in the context of anemia 2

Normal Ferritin (> 45 ng/mL)

• Indicates adequate iron stores
• Postmenopausal women typically have higher ferritin levels (median 71-84 μg/L) compared to premenopausal women (median 37-42 μg/L) 3, 5

Factors Affecting Ferritin Levels in Women

• Menstruation: Significantly lowers ferritin levels in premenopausal women 3, 4
• Hormonal contraception: Women using oral contraceptives have higher ferritin levels (median 62 μg/L) compared to non-users (median 42 μg/L) 4
• IUD use: Associated with lower ferritin levels (median 36 μg/L) due to increased menstrual bleeding 4
• Blood donation: Significantly lowers ferritin levels 4, 5
• Pregnancy and breastfeeding: Increase iron requirements and may lower ferritin 1
• Inflammation: Can falsely elevate ferritin levels; values < 100 μg/L may still indicate iron deficiency in inflammatory states 1

Management Recommendations

When to Investigate Low Ferritin

• Premenopausal women: Consider gastrointestinal evaluation when ferritin < 45 ng/mL with anemia 2
• Postmenopausal women: Gastrointestinal evaluation recommended when ferritin < 45 ng/mL with anemia 2

Treatment Targets

• Initial treatment target: Ferritin > 30 μg/L and transferrin saturation > 16% 1
• Maintenance target: Ferritin 30-100 μg/L 1
• Treatment duration: Continue iron supplementation for three months after normalization of iron parameters 1

Monitoring Recommendations

• Check ferritin and transferrin saturation after 4-8 weeks of treatment 1
• Monitor iron parameters every three months for one year after normalization, then annually 1

Clinical Pitfalls to Avoid

1. Relying solely on hemoglobin: Iron deficiency can exist with normal hemoglobin; ferritin is more sensitive for detecting early iron depletion 1

2. Using outdated ferritin cutoffs: The AGA strongly recommends using 45 ng/mL (not 15 ng/mL) as the diagnostic cutoff for iron deficiency in anemic patients 2

3. Ignoring inflammatory status: Inflammatory conditions can elevate ferritin levels, potentially masking iron deficiency 1

4. Overlooking menstrual factors: Duration and volume of menstrual bleeding significantly impact ferritin levels and should be considered when interpreting results 4

5. Missing non-menstrual causes: In postmenopausal women with low ferritin, gastrointestinal blood loss should be suspected and investigated 1