The effect of ultra-high hydrostatic pressure on selected hydrosoluble vitamins (B1, B6 and C) is studied. Vitamin retention after pressurization has been compared to that induced by several classic food processing treatments, such as pasteurization or sterilization. Ascorbate, pyridoxal, and thiamin hydrochloride, included in a multivitamin model system (mvMS), are analyzed by high performance liquid chromatography (HPLC), and under current operating parameters for the above processes. Thereafter, these vitamins indicate the impact of ultra-high hydrostatic pressure on the nutritional quality of tested matrices, on the basis of equivalent effects induced by several industrial treatments. Minor variations are found among the vitamins after pressurization. Vitamins B1 and B6 undergo no significant losses after the treatments. Vitamin C levels, although significant, are not dependent on the intensity of the ultra-high hydrostatic pressure process. Naturally occurring vitamin C losses are analyzed in two representative foodstuffs (egg yolk and strawberry coulis) after several processes, in order to validate the model system results. A survey of ascorbate retention has been carried out on ultra-high pressurized strawberry coulis, over 30 days. Results have shown that ultra-high hydrostatic pressure plays only a minor role in degradation kinetics of vitamin C. This article will integrate a general and structured evaluation framework, including other precise nutritional data of food processing.