The kidneys whose primary role is to filter extra water and waste products from the blood and balance the salts and minerals—such as calcium, phosphorus, sodium, and potassium—that circulate in the blood,  also release hormones that help make red blood cells, regulate blood pressure, and keep bones strong.

There are two main forms of kidney disease—acute kidney injury, which is often reversible with adequate treatment, and chronic kidney disease (CKD), which is often not reversible. CKD occurs slowly over many years, often due to diabetes or high blood pressure, while acute kidney injury happens because of illness or trauma or as an effect of certain medications. This can occur in a person with normal kidneys or in someone who already has kidney problems.

As CKD progresses, nutritional needs change.  It is possible to prevent or delay progression of CKD by eating the right foods and avoiding foods rich in sodium, potassium, and phosphorus. Therefore, it is recommended that a patient with reduced kidney function choose foods carefully to avoid complications.