Vitamin D is an important vitamin. It is the only vitamin that can be made by humans. The benefits of vitamin D include reducing bone loss, reducing fractures, prevention of tooth loss, maintenance of a healthy immune system and important links with blood pressure and diabetes Sources of vitamin D come from exposure to sunlight, ultraviolet light, and from the food we eat such as milk, fish, Eggs and cod liver oil. Low vitamin D levels may not cause obvious physical symptoms but can lead to several medical problems including thinning of the bones (osteopenia) osteoporosis and abnormalities in other blood tests. Severe vitamin D deficiency is rarely seen in United States due to commercially fortifed milk and foods. Low levels of vitamin D however may be caused by low dietary intake, lack of sun exposure, diseases of the intestinal tract (celiac disease, Crohn’s disease), cystic fibrosis and in patients having stomach or intestinal surgery such as the gastric bypass. Checking vitamin D levels requires a simple blood test that your doctor can order. If your level is low, your doctor may recommend one of several vitamin D replacement options for you. Current recommendations for vitamin D replacement therapy vary depending on your age, level of deficiency, and coexisting medical conditions. So, ask your doctor to check her vitamin D level.