Avocados are a great source of vitamins C, E, K, and B-6, as well as riboflavin, niacin, folate, pantothenic acid, magnesium, and potassium. They also provide lutein, beta-carotene, and omega-3 fatty acids. Avocados contain 25 milligrams per ounce of a natural plant sterol called beta-sitosterol. Regular consumption of beta-sitosterol and other plant sterols has been seen to help maintain healthy cholesterol levels.