The kidneys are also involved in the break down and disposal of large organic acids produced by the body. During this process, a special salt, called bicarbonate (a base), is lost from the body leading to the blood becoming slightly acidic. Healthy kidneys can cope with this loss by secreting more bicarbonate, allowing the blood to become less acidic. If the serum carbon dioxide level is below 20 the blood becomes very acidic. If the carbon dioxide level in the blood is greater than 30, the blood becomes too basic. The optimal carbon dioxide level should be approximately 24. As the kidney function decreases, our ability to maintain the appropriate acid-base balance is impaired and may require supplementation with medication.