Does ferritin (iron storage protein) level decrease during menstruation?

Ferritin Levels During Menstruation

Yes, ferritin levels do decrease during menstruation as the body mobilizes iron from storage to compensate for menstrual blood loss. 1

Mechanism of Ferritin Reduction During Menstruation

• Ferritin serves as the primary storage form of iron in the body, accounting for approximately 70-80% of iron stores in healthy individuals 1
• When menstrual blood loss occurs, the body mobilizes iron from storage (ferritin) to support ongoing erythropoiesis, resulting in measurable decreases in ferritin levels 1
• Women require additional iron to compensate for menstrual blood loss, estimated at 0.3-0.5 mg daily during childbearing years 2

Quantifiable Impact on Ferritin

• The average menstrual blood loss is approximately 59.3 ± 25.1g per cycle, with significant individual variation (range 24-110g) 3
• Menstrual blood loss is negatively correlated with serum ferritin levels - higher blood loss leads to lower ferritin levels 3
• A recent study found that menstrual blood loss accounts for approximately 8% of the explained variance in ferritin levels in premenopausal women, second only to time since last blood donation 4

Clinical Implications

• About 22.6% of menstruating women may be in an iron reduction period (serum ferritin <12 ng/ml) even without clinical anemia 3
• Women with heavy menstrual bleeding (≥80 mL/month) have significantly lower ferritin levels, affecting approximately 10% of women of childbearing age 1
• Iron requirements for female adolescents and women are higher (0.35 mg/kg) than for males (0.2 mg/kg) specifically to compensate for menstrual blood loss 1

Physiological Adaptations

• During adolescence, hepcidin levels (the primary regulator of iron absorption) decrease in response to hormonal changes, representing a regulatory mechanism to adapt to increased iron demands from both growth and menstrual blood loss 1
• This physiological adaptation helps increase iron absorption but may not be sufficient to prevent iron depletion in women with heavy menstrual periods 1

Important Considerations

• Normal hemoglobin levels do not necessarily indicate adequate iron status - serum ferritin is a more sensitive indicator for iron nutritional status 3
• Use of hormonal contraceptives, particularly levonorgestrel-releasing intrauterine devices, is associated with decreased risk for iron deficiency by reducing menstrual blood loss 1, 4
• After menopause, women may experience a significant increase in ferritin levels due to the cessation of menstrual blood loss, as demonstrated in a case report of porphyria cutanea tarda exacerbation at menopause 5

Clinical Management Implications

• For female athletes and women with heavy menstrual bleeding, more frequent monitoring of iron status is recommended 1, 6
• Iron supplementation should continue for three months after hemoglobin normalization to ensure adequate replenishment of iron stores 7, 6
• Discontinuing iron therapy prematurely can lead to recurrence of iron deficiency, as body stores may remain depleted even when hemoglobin has normalized 6