The increasing prevalence of online courses has highlighted the importance of digital literacy for students. This study investigates the relationship between digital literacy and academic achievement among students who participate in an online course on anatomy and physiology. The study also evaluates how different aspects of digital literacy, such as age and previous education in natural science, affect students' grades. Using logistic regression analysis, data from five areas of digital literacy that were assessed among participants with different educational backgrounds are analyzed. The results show that some aspects of digital literacy are more crucial for academic success in the online course. Students with a natural science background exhibited higher levels of digital literacy, emphasizing the importance of considering previous education in supporting students' digital skills in online courses. The study also reveals that students were proficient in self-assessing their own digital literacy, enabling easy evaluation of the collective digital literacy within the course and facilitating targeted interventions for all students, regardless of their initial digital literacy levels. This study underscores the importance of digital literacy in online education. It highlights the specific areas of digital literacy that strongly contribute to academic achievement and emphasizes the positive impact of previous education in natural science on students' digital skills. These findings suggest that instructors should consider these factors when designing and delivering online courses to ensure equal opportunities for students to enhance their digital literacy.