Amarasingha D.Silva R.Perera L.Wickramasinghe N.Piyathunga D.Gooneratne L.Jayatissa R.Dharmabandu S.Chen P.Fucharoen S.Perera S.Premawardhena A.Mahidol University2026-05-092026-05-092026-12-01Scientific Reports Vol.16 No.1 (2026)https://repository.li.mahidol.ac.th/handle/123456789/116635Previous studies in Sri Lanka have explored the prevalence and causes of anaemia, mainly emphasizing iron deficiency while overlooking other important factors such as enzymopathies, membranopathies, and haemoglobinopathies. Moreover, many studies reported unexplained cases of anaemia even after detailed evaluation. This study aimed to determine the prevalence and underlying causes of anaemia among community-based young adults in Sri Lanka. A descriptive cross-sectional study was conducted from January 2023 to December 2024 among young adults aged 18–30 years. Data and blood samples were collected using a pretested questionnaire. Anaemic individuals underwent serum iron studies, CRP, vitamin B12 and folate assays, and thalassaemia screening. Those with uncharacterized anaemia were further assessed using red cell enzyme assays, EMA dye binding assays, and whole-exome sequencing. The mean (± SD) age of the study participants was 23.90 ± 1.98 years. Anaemia prevalence was 15.0%. The main causes were iron deficiency (49.3%), folate deficiency (27.8%), vitamin B12 deficiency (14.4%), and haemoglobinopathy traits were identified in 25.6% of anaemic individuals, frequently in combination with nutritional deficiencies. A substantial proportion of anaemic individuals exhibited coexisting aetiologies rather than a single cause. Initially, 17.4% remained uncharacterized, but advanced testing identified variants suggestive of hereditary spherocytosis and congenital dyserythropoietic anaemia or dyskeratosis congenita. This first community-based Sri Lankan study integrating advanced diagnostics revealed that, although iron deficiency predominates, genetic and enzymatic disorders contribute notably, highlighting the need for broader diagnostic strategies in anaemia screening in the community.MultidisciplinaryArticleSCOPUS10.1038/s41598-026-44168-22-s2.0-10503759120720452322