Key takeaways:
- Heavy menstrual bleeding was common, affecting more than half of adolescents in the study and significantly increasing iron deficiency risk.
- Iron deficiency was nearly twice as prevalent in adolescents with heavy menstrual bleeding compared with those without.
- Meat-restricted diets further amplified iron deficiency risk, particularly when combined with heavy menstrual bleeding.
- Despite high rates of iron deficiency, iron supplement use was low across all dietary and bleeding groups.
- Findings highlight the need for improved screening for heavy menstrual bleeding and dietary iron intake in adolescent care.
Iron deficiency (ID) is significantly more likely in adolescents with heavy menstrual bleeding (HMB), according to a recent study published in PLOS One.1
Increased iron requirements during puberty lead to greater rates of ID among adolescent girls, leading to symptoms such as muscular weakness, reduced physical performance, fatigue, and impaired cognitive function.2 HMB also significantly impacts women’s health, impairing physical, social, emotional, and material quality of life.1
“There is a knowledge gap regarding the impact of HMB and dietary iron intake on ID in adolescents. Additionally, there is a lack of accurate and accessible tools for screening for HMB in this age group,” wrote investigators.
Assessment of dietary iron intake
The cross-sectional study was conducted to evaluate rates of HMB among adolescents and identify its link with dietary habits and ID. Patients aged at least 15 years who had experienced menarche and without bacterial infection, current pregnancy, or chronic inflammatory diseases were eligible for inclusion.
A digital questionnaire was provided to obtain participant age, height, weight, age at menarche, contraceptive use, bleeding patterns while using hormonal contraceptives, smoking, iron-supplement intake, and snus use. Selected questionnaire items were also used to determine dietary habits.
Patients with no dietary restrictions were classified as omnivores, and those avoiding red meat were considered to be following a meat-restricted diet. This was used as a substitute for low dietary intake of heme iron.
Heavy menstrual bleeding scoring
A validated questionnaire assessed HMB through questions about bleeding for more than 7 days, 3 or more days of heavier bleeding than normal, menstruation being bothersome because of its abundance, spotting at night, worrying about staining furniture, and avoiding activities during heavier bleeding.
Three points were given for affirmative responses to items 1 and 3, vs 1 point for every other question. Patients with 3 or more points were considered to have HMB. Non-fasting blood samples were collected by registered nurses and assessed using the Atellica IM Analyzer and Sysmex XN-10 for ferritin and hemoglobin levels, respectively.
ID was defined as serum ferritin under 15 µg/L, and anemia as hemoglobin under 120 g/L. Non-anemic patients with iron deficiency were recommended to take an iron supplement for 3 to 6 months.
Prevalence of heavy menstrual bleeding and reported impacts
There were 477 initial participants, 12.2% of whom used combined oral contraceptive pills, 2.7% etonogestrel subdermal implant, 1.9% levonorgestrel intrauterine system, and 1% progestin-only pills. Of this cohort, 394 patients aged a mean of 16 years and with a median body mass index of 21.2 were included in the final analysis.
A median age at menarche of 12 years was reported, and a meat-restricted diet was identified in 27.9% of participants. Additional rates included:
- An HMB score of at least 3 in 52.8%
- Worrying about staining furniture in 66.8%
- Avoiding activities in 37.6%
Self-rated health did not differ between patients with vs without HMB, and iron supplement use was reported in only 6.8% of the former group vs 7.5% of the latter. Additional iron supplement rates included 5.6% in omnivores and 11.6% in those with meat-restricted diets. ID was reported in 39.8% of patients overall, 51.9% with HMB, and 26.3% without HMB.
Implications
Patients with HMB were also more often anemic, with a rate of 12.5% vs 4.3% among those without HMB. All dietary groups reported low ferritin levels, but patients with both HMB and a meat-restricted diet reported the highest rate of ID at 70.9%. Overall, the data highlighted significant rates of ID among adolescent girls, linked to both HMB and a meat-restricted diet.
“These findings underscore the importance of identifying and addressing both iron loss and low iron intake when screening for and preventing ID in adolescents,” wrote investigators.
References
- Söderman L, Stubbendorff A, Ladfors LV, Borgström Bolmsjö B, Nymberg P, Wolff M. Exploring the effect of menstrual loss and dietary habits on iron deficiency in teenagers: A cross-sectional study. PLOS One. 2025. doi:10.1371/journal.pone.0336688
- Dimas-Benedicto C, Albasanz JL, Bermejo LM, et al. Impact of iron intake and reserves on cognitive function in young university students. Nutrients. 2024;16(16):2808. doi:10.3390/nu16162808
