Vitamins are organic compounds that are required for various biological functions. In general, vitamins are not synthesized in the human body, but lack or deficiency of them may lead to certain diseases. Determinations of 11 vitamins in various products were performed, which included ascorbic acid (C), seven vitamins of the B group (thiamine B 1 , riboflavin B 2 , nicotinamide B 3 , pantothenic acid B 5 , pyridoxine B 6 , folic acid B 9 , and cyanocobalamin B 12 ), as well as three fat-soluble vitamins (retinol A, cholecalciferol D 3 , and α-tocopherol E). A column with RP18 stationary phase and a diode array detector with properly selected analytical wavelengths for each compound were used. A gradient of trifluoroacetic acid in water with methanol was used as the mobile phase. Limits of quantification in the range of 0.70-2.90 μg/mL for watersoluble vitamins and 1.85-15.84 μg/mL for fat-soluble vitamins were obtained. Those values are sufficient for determinations of the aforementioned compounds in foodstuff. The developed procedure of sample preparation together with chromatographic system can be used for food quality monitoring in the food industry.