Walnuts are a good source of vegetable protein and fat as half to two thirds of their weight consists of fat. Furthermore, walnuts have one of the highest content in omega-3 fatty acids while the ratio of linoleic acid (omega-6 fatty acid) to alpha-linolenic acid (omega-3 fatty acid) is 4:1. Walnuts are rich in vitamins A, B and E as well as folic acid, the adequate intake of which is essential for women during their first months of pregnancy or who intend to become pregnant. Walnuts are also a good source of non-heme iron, necessary for the development of red cells, and potassium, which helps control blood pressure and reduce cardiovascular risk.