in addition to classical effects and toxicity risks due to excessive Vitamin D intake. As is known, Vitamin D is becoming more and more understandable every day, and new studies are needed. However, as a result of the literature reviews done in this study, it was investigated the cause-and-effect relationship of toxicities risks, diseases determined due to Vitamin D insufficiency or Vitamin D deficiency, determination of treatment doses, and health policy applied to prevent Vitamin D insufficiency and toxicity, it is seen that it is important to use standard methods enriched with controlled studies. Keywords: Chronic diseases, Vitamin D deficiency, Vitamin D toxicity, Vitamin D
Corresponding Author: Buyuker S.