This study evaluated the knowledge, attitude and practice towards vitamin D deficiency among Saudi population. A cross-sectional study utilizing an online survey was conducted. Descriptive statistics was applied. About 98.4% heard about vitamin D, most of them knew that the sun is important source of vitamin D, unfortunately only 46.4% of participants who is like going out to sun. A few of participants (13.7%) thought that they have sufficient sun exposure. Majority of participants 93.1% knew that vitamin D is important for bone health, and 48.4% of participants knew the presence of relation between vitamin D deficiency and other diseases such as diabetes, cardiovascular, and depression. In addition, the most of participants (91.0%) reported that vitamin D source was the sun. This study found inadequate knowledge, and poor practice about vitamin D deficiency. More efforts should be carried out for the public to improve their knowledge and attitude about vitamin D.