Vitamin D deficiency is now recognized as a worldwide health disease . The major cause of vitamin D deficiency is the lack of appreciation that sun exposure in moderation is the major source of vitamin D for most humans. Very few foods naturally contain vitamin D, and foods that are fortified with vitamin D are often inadequate to satisfy either a child’s or an adult’s vitamin D requirement. Vitamin D deficiency causes rickets in children and will precipitate and exacerbate osteopenia, osteoporosis, and fractures in adults. Vitamin D deficiency has been associated with increased risk of common cancers, autoimmune diseases, hypertension, and infectious diseases. Vitamin D can be easily assessed in patients by measuring serum 25- hydroxyvitamin D. The aim of this study was to estimate vitamin D3 levels in patients coming to medicine and orthopaedic OPD with various symptoms related to vit D deficiency such as tiredness and fatigue, muscle pain, bone and joint pain, mood changes, low immunity (recurrent respiratory infections), hypertension . Both male and females 70 adult subjects were included in this study. Serum Vitamin D3 levels were estimated in all subjects. 35.71% subjects had severely deficient vit D3 levels. 42.85% were deficient. 14.28% had inadequate vitamin D3 levels. 4.28% had adequate levels of Vitamin D3 . Vitamin D deficiency can be managed with pharmacological or non-pharmacological approaches depending on the severity. The goal of the treatment is to raise serum vitamin D to normal levels to relieve the symptoms and reduce the adverse health outcomes such as rickettsia among infants, osteomalacia among adults, and osteoporosis among the elderly