DHA (Oil, Powder)-is an omega-3 fatty acid found in cold water fatty fish. Vegetarian sources of DHA can be found in seaweed and algae. DHA is essential for the proper functioning of our brains as adults, and for the development of our nervous system and visual abilities during the first 6 months of life. In addition, omega-3 fatty acids are part of a healthy diet that can help lower the risk of heart disease.