Öz
Vitamin D deficiency and insufficiency are among the important health problems worldwide. Vitamin D, which is synthesized by sun exposure (specific wavelength ultraviolet UVB rays), is known to act as a natural protector, preventing and delaying many chronic and autoimmune diseases, as well as its regulatory role in calcium and phosphate metabolism. People and other creatures need vitamin D to keep their lives healthy and strong. In this review, after briefly mentioning the importance of vitamin D for health, information based on the studies in the literature has been presented about the creatures rich in vitamin D metabolites, especially for the purpose of people to benefit from other organisms as a source of vitamin D. Although there are few ecological data on this subject, various findings have been compiled about the species that synthesize and accumulate vitamin D, which we can use as natural sources. In the studies done, phytoplanktonic algae, reindeer lichen, fungi and also fish and lichens accumulating vitamin D are among the creatures that produce high amounts of vitamin D with the effect of UVB. In addition, in this study, explanatory information on the photochemical synthesis metabolism and biology of the vitamin D and the biological and environmental factors affecting the formation of vitamin D are included. This review focuses on the potential of living things that can provide a predictable vitamin D source for humans.