Now coming to the cooking part, there have been reports that cooking vegetables can degrade the nutrients present in them. It is said that the way you prepare vegetables can alter their nutritional qualities. For example, water-soluble vitamins, such as B & C are quite sensitive to cooking methods. These vitamins have a tendency to leach out of veggies when boiled and can be degraded by heat. However, when it comes to fat-soluble vitamins such as A, D, E and K, they work better during the cooking process. When it comes to minerals, heat can improve the ability of some to be digested, absorbed and metabolized.