A living tissue needs nutrients to survive and bone physiology should be balanced in order to be healthy. Vitamin D plays a critical role for both bones and other body tissue homeostasis. Various conditions have been found to be associated with low vitamin D and low levels of vitamin D in the bone can manifest from childhood. Other medical conditions (extra osseous) have also been found to be associated with low vitamin D. Currently the world is under attack from the Covid-19 pandemic, but reports indicate that we would benefit if the levels of vitamin D are optimum. Vitamin D enhances both the innate and cellular immunities that are crucial in fighting against the microorganisms that cause various infections. Studies report the prevention of respiratory tract infections if the levels of vitamin D in the body are optimal. Mechanisms of prevention include lower viral replication and reduction of an inflammatory process in the lungs. Various medical conditions can affect the bone directly or indirectly. Some literature studies have shown that there could be an association between low vitamin D and medical conditions, including orthopaedic conditions. Other secondary bone diseases can be prevented if the level of vitamin D is within normal range. We believe that giving patients vitamin D can reduce the cost of operations as well increase patients' lifespan. The aim of this review article is to outline the benefits of vitamin D for both osseous and non-osseous conditions and also to convey the importance of knowledge of vitamin D supplementation for an orthopaedic surgeon.