Objective: Vitamin D is an essential hormone in calcium, phosphor and bone metabolism. Skin synthesizes great amount of vitamin D in sun light, it can also be taken by diet. Vitamin D deficiency may occur in settings with low sunlight exposure. Medical personal are under risk for vitamin D deficiency, especially who works at night shifts and in low sun-exposed buildings. Our aim was to determine vitamin D levels of medical personal and evaluate effect of working time and place on vitamin D levels.