Mostly green leafy vegetables and bitter melon.
Yam.
Sodium and potassium are the electrolytes that maintain the proper blood balancing. These electrolytes are some times reabsorbed from the consumed food during the process of purification in the kidney.
Edward, a character in the Twilight series, does not consume human food due to his vampire nature. Instead, his diet consists of blood to sustain him.
The kidneys handle it
Kidneys
Animals have to consume food as they cannot make their own food
The liver and kidneys have the important rules in blood purification.
Only vampire bats consume blood as their source of food. Other bats eat insects, amphibians, small animals and fruit.
lungs
Blood
The blood carries both nutrients (food) and wastes to and from cells. At the lungs carbon dioxide is exchanged for oxygen and at the kidneys blood is filtered and wastes and some water is lost. Most of the water is retained.
both the lungs for purification
Mosquitos (females only) bite to get a drink of blood, which they consume as food. Then they fly off.