Vitamin D (VD) insufficiency is becoming an important problem among Saudi nationals. This population will probably keep suffering from vitamin D deficiency because there is a lack of understanding about lifestyle changes that can prevent Vitamin D insufficiency. The aim of the study to assess the level of knowledge, attitudes, and practices associated with Vitamin D among the adult residents of Arar in the Northern Border region of Saudi Arabia. A descriptive cross-sectional study was done among the general adult population in Arar city using a well-structured and well-designed questionnaire. The study finding showed that over two-thirds (69.6%) of respondents reported a high level of vitamin D knowledge on the scale of respondents' attitudes toward vitamin D. Considering the respondents' attitude scale about vitamin D, 75 percent of them showed a moderate level, and the level of practices of vitamin D use show that over forty percent have a moderate level. This study showed that the participants had a high level of vitamin D knowledge and attitudes. Although most participants were aware of the sources, benefits, and risks of a vitamin D overdose, most of them did not take part. The majority of them spent most of their time indoors due to cultural considerations, which reduce the production of vitamin D.