Prevalence and factors associated with iron deficiency among regular blood donors in Regional Hospital, Southern Thailand: a cross-sectional study

Abstract Blood donation is a major cause of iron deficiency (ID). Eventually, hemoglobin concentration lower than reference limits leads to temporary deferral from blood donation eligibility. Multiple factors are associated with ID among blood donors. The objective of this study was to determine the prevalence of iron deficiency among southern Thai blood donors, evaluate their hematological profiles, and identify factors associated with ID. A cross-sectional study was conducted from January to July 2024, enrolling 350 regular voluntary blood donors in Southern Thailand. Participants provided venous blood samples and answered questionnaires regarding demographics and donation history. Hematological parameters were analyzed using an automated cell counter, and plasma ferritin levels were measured using chemiluminescent immunoassay to classify iron status into Iron Depleted Erythropoiesis (IDE), Absent Iron Stores (AIS), or Iron Deficiency Anemia (IDA). The overall prevalence of iron deficiency was 22.29%, comprising 10.57% IDE, 9.14% AIS and 2.57% IDA. Female donors had a significantly higher prevalence of ID (32.73%) compared to males (12.97%). All ID stages showed significantly reduced hemoglobin and hematocrit compared to non-ID donors ( p < 0.05). AIS and IDA showed a significantly increased RDW compared to non-ID donors ( p < 0.05). Male ferritin differed significantly according to BMI, donation frequency, and duration of last donation, whereas female ferritin levels were significantly higher in the age group (> 50 years) compared with those ≤ 29 years. Specifically, Female sex, age, BMI and donation frequency were associated with iron deficiency among regular blood donors. Female sex was associated with higher odds of ID compared with male sex. Similarly, donor with age of 17–29 years, normal BMI and overweight status showed increased odds of ID compared with their reference groups. In contrast, donors with 11–15-time cumulative donations showed lower odd of ID. ID was highly prevalent among regular southern Thai blood donors, particularly females. Implementing Ferritin-based screening could facilitate earlier identification of iron depletion that is undetectable through routine hemoglobin screening alone.