How Onion Affects Kidney Disease?

How onion affects kidney disease? According to an American health association, onion is one of top 15 healthy food for people with kidney disease which follows: red bell peppers, cabbage, cauliflower,garlic, apples, blueberries, strawberries, red grapes, cherries ,egg white, olive oil, fish and so on.
For people on a kidney diet looking to add more flavors to foods, try using a variety of onions including white, brown, red and others. Eat onions raw on burgers, sandwiches and in salads, cook them and use as a caramelized topping or fry them into onion rings. Include onions in recipes such as Italian Beef with Peppers and Onions.
Experts in nutrition and health field report that 100g onion contains 1.8g protein, 8g carbohydrate, 8mg calcium, 1.8mg iron and vitamins such as B2, B6, C and E, etc. In addition, it nearly contains no fat, which is good for kidney disease patients indeed.