The prevalence of vitamin D deficiency has recently been recognized in different parts of the world, even affecting healthy populations. The deficiency of vitamin D can lead to rickets in children and osteomalacia in adults. Few studies have been done to evaluate the status of vitamin D in the medical community around the world. No studies have been done in Libya to evaluate the status of vitamin D in medical students. This study aimed to evaluate the prevalence of low levels of vitamin D among healthy Libyan medical students in the first year at the University of Tripoli, Tripoli. A prospective study was conducted on 100 medical students in the first year in the Faculty of Medicine with a mean age of 19.5 years, 38 males and 62 females. Blood samples were taken and investigated for different biochemical parameters including serum calcium, serum vitamin D and serum parathyroid hormone levels. A questionnaire containing different data was completed for each student including personal data (age, address, nationality, and other data related to vitamin D deficiency. The prevalence of vitamin D deficiency in all the participating students was 74.0% (58.7% in males and 83.8% in females), while 21.0% had vitamin D insufficiency (28.0% in males and 16.12% in females). Only 05.0% of the students who had normal vitamin D were males. The mean 25-hydroxy vitamin D level was 19.49±8.56 ng/ml in males and 12.08±6.70 ng/ml in female students. The statistical analysis revealed that there is a highly significant difference among the students in vitamin D deficiency. In conclusion, low concentration of vitamin D is highly prevalent among the medical students included. Urgent action has to be taken to prevent adverse consequences of low vitamin D in the young population.