Differences and Correlations in Nutrient Intake and Hematological Markers Between Iron-Deficient and Non-Iron-Deficient Female Basketball Players: A Preliminary Study

Background/Objectives: Iron deficiency (ID) can occur before anemia and may impair performance, recovery, and hematological function, particularly in athletes. Female basketball players may be especially vulnerable due to high training demands and sex-specific iron losses. Therefore, this study aimed to compare nutrient intake and hematological and iron status biomarkers between ID and non-ID female basketball players, and to examine diet–biomarker correlations. Methods: Twenty-four female basketball players completed the study. Athletes were stratified by ferritin, with ID defined as <30 μg/L, resulting in 12 athletes per group. Dietary intake was assessed using a 48 h food record. Energy, macronutrients, fiber, iron, calcium, folate, vitamin B12, and vitamin C intakes were analyzed. Blood biomarkers included red blood cells (RBCs), hemoglobin (HGB), hematocrit (HTC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), ferritin, serum iron, transferrin, total iron-binding capacity (TIBC), and unsaturated iron-binding capacity (UIBC). Results: ID athletes had significantly lower fiber, iron, folate, and vitamin C intakes than non-ID. They also showed significantly lower HGB, HTC, MCV, MCH, and ferritin, and higher transferrin, UIBC and TIBC. Iron intake correlated positively with HGB, HTC, MCV, MCH, serum iron, and ferritin, and negatively with UIBC. Conclusions: Iron deficient female basketball players may present less favorable dietary profiles and altered hematological and iron status biomarkers. In this context, quarterly assessment of iron status biomarkers should be supported by nutrition education aimed at improving iron intake, alongside monitoring of energy and macronutrient intake in relation to training load. These approaches may help identify athletes requiring nutrition-focused support, although larger studies with longer-term dietary assessment are warranted.