The objective of this study was to determine the knowledge, attitude and practices of the use of vitamin supplements among patients visiting security forces hospital located at Al-Dammam of the Kingdom of Saudi Arabia. Total 236 patients were interviewed during the period of January 2015 to April 2015. A pre-tested and structured questionnaire was used to collect information. It consisted of questions regarding demographi, awareness of vitamin supplements and its consumption, reasons for usage and its effects. After obtaining written consent, eligible individuals were interviewed. The results revealed that 58.90% of the respondents were not aware of vitamin supplements. The most known vitamin was found to be Vitamin C (57.63%) with Vitamin K being the least well known(2.54%); while 73.97% of the respondents were unaware of the harmful effects of vitamin supplements. The results also showed that 41.10% of the study population had taken vitamin supplements, and 79.24% of the participants considered that vitamin supplements to be helpful. Taking vitamin supplements to improve general health was the most frequently chosen answer(59.75%) as the reason for use of vitamin supplements. On the other hand, a majority of the population was unaware of the indications for use of vitamin supplements. This study highlights a very significant yet ignored issue of vitamin supplementation in Al-Dammam region of the Kingdom of Saudi Arabia. Since awareness about the use of vitamin supplements seems to be deficient in the Al-Dammam region of the Kingdom of Saudi Arabia, a need exists to inform the general population about the use of vitamin supplementation.