Abstract: The five parameters geometrical progression fitting approximation has been used to calculate energy absorption buildup factor (EABF) and exposure buildup factor (EBF) for some Vitamins and tissue equivalent materials in the energy region 0.015-15.0 MeV up to a penetration depth of 40 mfp. Variation of EABF with incident photon energy and penetration depth has been studied. We observed that chosen Vitamins have maximum value of EABF and EBF around 0.1 MeV and that of TEM around 0.08 MeV. Variation in value of EABF was due to dominance of different interaction processes in different energy regions. Bee Wax has the maximum EABF and EBF at 0.08 MeV and all the samples except Vitamin A1 have maximum EBF at 0.1 MeV.