Boiling vegetables can degrade the nutritional value both in minerals and vitamins. The things that affect it is cooking time and whether it is in water or not. Additionally, some vitamins are more “fragile” than others, such as vitamin C, folate, and potassium, and are more easily lost. As a general rule, when boiling try to include as much of the cooking water in your final meal or keep it as vegetable broth. Additionally, minerals are best preserved with dry cooking, while vitamins with boiling, duo to the shorter cooking time.