One of the most prevalent dietary deficiencies among female college students is iron deficiency (ID), which has a detrimental impact on general health, focus, and physical activity. Low serum ferritin levels (SFLs) are usually a sign of this disease. The present investigation aims to examine the relationship between ID, healthy nutrition, caffeine consumption, and the menstrual cycle among girls at the university stage in Al-Bayda City, Libya. This study was conducted from April 1 to May 30 in 2025. It targeted female university students whose ages ranged from 18 to 22 years. Blood samples were collected from the 223 participants after obtaining their consent, and with responded to the questionnaire, which included questions related to nutrition, caffeine consumption, and menstrual cycle patterns. The samples were then transferred to the laboratory for measurement of SFLs. This study revealed that 73% of university female students were iron-deficient, while 27% were non-deficient, with SFLs markedly lower in the iron-deficient group compared to the non-deficient group. Age was not significantly associated with ID. Moreover, the statistics revealed a significant relationship between dietary habits and ID among the participants. Additionally, results showed energy drink intake was significantly higher in the deficient group. Also, no significant differences were found in tea or coffee and cycle regularity and ID among the participants. The findings of this study indicate that ID is a common health concern among female university students, and several other factors emerged as strong predictors of ID, reinforcing the importance of confirming clinical suspicion with laboratory assessments like SFLs.................... Keywords: ............Iron deficiency; nutrition; ferritin; university girls.