The aim of this paper is to describe the properties of vitamin D and to create an infrared spectrum for different samples of vitamin D. Vitamin D supports the absorption of calcium in the bones and as such is responsible for the proper formation of bones. People who are sufficiently exposed to sunlight get vitamin D through their skin, and it is also possible to take it through food and various nutritional supplements. Deficiency of vitamin D brings with it numerous negative consequences, some of which are: higher chances of getting cancer, suffering from cardiovascular diseases and the development of allergies and asthma. Nowadays, a large number of people suffer from symptoms caused by a lack of vitamin D. Sedentary lifestyles, busy lives and business opportunities have contributed to the fact that people spend as little time in the air as possible, and at the same time in the sun, which is why vitamin D deficiency occurs No, today there are different types of supplements that can replace vitamin D. In the framework of this work, infrared spectroscopy was used to record spectra for vitamin D2, D3, and for a mixture of vitamin D, zinc, and vitamin C. Also, for the mentioned vitamins, calculations were performed in the program package Gaussian 09. The calculated spectra, as well as the experimental ones, show peaks characteristic for vitamin D. Thus, characteristic peaks for the isopropyl group, for C-H bonds, for C=C bonds, for C-O bonds and O-H-O bonds are observed. Finally, by comparing the recorded and calculated spectra, it is clearly visible that the calculations confirm the recorded spectra well.