Basil is an herb in the mint family. It adds flavor to meals, and its nutrients may provide health benefits. It is an excellent source of vitamin K, manganese, iron, vitamin A, and vitamin C. It's also a good source of calcium, magnesium, and omega-3 fatty acids. Basil isn't simply for internal use. When basil's oils are extracted to make an essential oil, it is used for treating cuts, wounds, and skin infections.