Lettuce is one of the favourite mature green leafy vegetables. Its crispy, green leaves are one of the incredible sources of essential nutrients that benefit health. Used mostly in crunchy green salads or healthy sandwiches, they are year-round sources of vitamin A, vitamin C, and other nutrients. Buy it online fast delivery! Lettuce provides significant amounts of vitamins A and K. They have a high water content, making them a refreshing choice during hot weather. They also provide calcium, potassium, vitamin C, and folate.