Final answer:
Water-soluble vitamins in foods can be destroyed by heat, exposure to air and light, and boiling.
Step-by-step explanation:
Water-soluble vitamins in foods can be destroyed by three factors: heat, exposure to air and light, and boiling. When foods, especially vegetables, are cooked, water-soluble vitamins such as B and C can dissolve into the water used for cooking. When the water is discarded, these vitamins are lost.