Rajma is a legume which is packed with vital nutrients such as copper, iron, manganese, phosphorus, vitamins K1 and folate. Also known as kidney beans, rajma also has an abundance of fibers which makes it a healthy staple for those who want to lose weight. Here are the 5 incredible health benefits of kidney beans/rajma. When making a rajma recipe ensure to cook it completely as raw or improperly cooked rajma can cause diarrhea and vomiting.