Water Pumpkin vegetable is one of the widely grown vegetables incredibly rich in vital antioxidants, and vitamins. Though this humble backyard vegetable is less in calories, nonetheless, it carries vitamin A, and flavonoid poly-phenolic antioxidants such as lutein, xanthin, and carotenes in abundance. water Pumpkin is a storehouse of many anti-oxidant vitamins such as vitamin-A, vitamin-C and vitamin-E.