Abstract
BACKGROUND: Significant physiological changes occur in adolescence, including the onset of menarche in girls. However, the extent to which menstrual bleeding contributes to anaemia and micronutrient deficiencies remains unclear. This study assesses the prevalence of anaemia and micronutrient deficiencies and examines their association with menarcheal status, menstrual bleeding severity and other factors among adolescent girls in Lebanon. METHODS: Data were collected as part of a nationally representative cross-sectional study involving 2254 adolescent girls, 10-19 years of age. Household interviews were used to gather information on household demographics and wealth, and individual interviews assessed dietary diversity, menarcheal status and menstrual bleeding severity (assessed for post-menarche girls only). Blood samples were analysed to determine haemoglobin, ferritin, retinol-binding protein, folate and vitamin B12 levels. We used multivariable models to identify factors associated with anaemia and deficiencies in iron, folate, vitamin B12 and vitamin A. RESULTS: Overall, 20.3% of girls had anaemia, 29.5% iron deficiency, 13.9% iron deficiency anaemia, 14.4% folate deficiency, 17.7% vitamin B12 deficiency and 3.9% vitamin A deficiency. Among post-menarche adolescent girls, 22.4% reported severe menstrual bleeding. Bleeding severity was significantly associated with iron deficiency and iron deficiency anaemia in multivariable models. Iron deficiency was the primary predictor of anaemia, and a significant dose-response relationship was found between menstrual bleeding and anaemia in iron-deficient girls. Post-menarche status, but not bleeding severity, was associated with 46% and 54% higher prevalence of B12 and folate deficiencies, respectively. Neither menarcheal status nor bleeding severity was associated with vitamin A deficiency. CONCLUSION: Among adolescent girls in Lebanon, anaemia and micronutrient deficiencies were common, and menstrual bleeding severity was strongly associated with iron deficiency and anaemia in iron deficient girls. Menstrual health is a key predictor of nutritional status in adolescent girls and should be integrated into health programmes and nutrition assessments.