abstract: In this study we tested the hypothesis that a product subjected to a single treatment in water (modified technology – a convenience food) will contain more magnesium than the one subjected to a twofold treatment (traditional technology). Moreover, with higher magnesium retention, the nutrient density (ND) of the product will also be higher, as will be the intake of magnesium in a portion of vegetables expressed as a percentage of recommended dietary allowance (RDA). In fresh vegetables, the highest magnesium content was found in spinach and the lowest in white cauliflower. In vegetables prepared for consumption, magnesium retention was highest in frozen products obtained using the modified technology, followed by cooked fresh vegetables, with the lowest retention in product obtained using the traditional technology. The above sequence of magnesium content also applied to ND and RDA values, the ND values easily exceeding 100% for all the samples examined.