How many points do ferritin levels drop during menstruation?

Ferritin Decrease During Menstruation

During menstruation, ferritin levels typically drop by approximately 1 mg per cycle in women with normal menses, while women with menorrhagia (excessive menstrual bleeding) experience a significantly higher drop of 5-6 mg per cycle. 1

Iron Loss During Menstruation

• Average iron loss during normal menstruation is approximately 0.87 mg per cycle (range 0.102-2.569 mg) 1
• Women with menorrhagia lose significantly more iron, with median losses of 5.2 mg per cycle (range 1.634-8.665 mg) 1
• The duration of menses directly influences serum ferritin concentration 2

Impact on Iron Stores

• Approximately 22.58% of menstruating women may be in an iron reduction period (serum ferritin < 12 ng/ml) even without clinical anemia 3
• In women with normal menses, mean serum ferritin levels are around 36.2 ng/ml (range 8.6-100 ng/ml) 1
• Women with menorrhagia typically have much lower ferritin levels, averaging 6.4 ng/ml (range 5-14 ng/ml) 1
• A substantial proportion of women (20-60% depending on diet) may have low iron stores (serum ferritin <10 μg/L) 4

Factors Affecting Iron Status During Menstruation

• Menstrual blood loss is negatively correlated with serum ferritin levels 3
• Diet type significantly affects iron status in menstruating women 4:
  • Poultry/fish diets are associated with higher iron stores than lacto-ovo-vegetarian diets 4
  • Intakes of meat, dairy products, and coffee have significant effects on serum ferritin concentration 2
• Contraception method impacts iron status:
  • IUD use can lead to iron deficiency in up to 71% of users after 6 months 5
  • Oral contraceptive use has no adverse effect on iron balance long-term 5

Clinical Implications

• Serum ferritin is the most specific indicator available for depleted iron stores in menstruating women 6
• In women of childbearing age, ferritin ≤15 μg/L has 75% sensitivity and 98% specificity for iron deficiency 6
• Iron stores can be depleted even without clinical anemia, making serum ferritin a more sensitive indicator for iron nutritional status than hemoglobin 3
• After iron depletion therapy in patients with hemochromatosis, serum ferritin levels decrease significantly within 3-4 months due to regular blood losses 7

Monitoring Considerations

• For women with excessive menstrual bleeding, monitoring iron status is essential as they are at significantly higher risk of iron deficiency 1
• Identifying individuals with high menstrual losses should be a key component of strategies to prevent iron deficiency 4
• When evaluating iron deficiency anemia, a ferritin cut-off value of 45 μg/dL is recommended as it provides an optimal balance of sensitivity and specificity 7