Fats or Lipids
Dietary fats (or lipids) are one of the two main sources of energy for the body. In addition, they (as well as related nutrients such as cholesterol) are a critical structural and functional part of the membranes surrounding all cells in the body (particularly the nervous system). They are important in the making of many critical hormones (including prostaglandins).Many people with kidney disease suffer from lipid disorders (including high cholesterol), which increases their risk for cardiovascular disease dramatically. Therefore, it is important for people with kidney disease to monitor their LDL and cholesterol closely.
Carbohydrates
Carbohydrates (or sugars and starch) are the other main source of energy for the body and come mainly from cereals and grains. Although a certain amount of carbohydrates are stored in the body as glycogen (mainly in the liver), excess carbohydrates are converted into fat for long-term storage. People with kidney disease suffer the same adverse affects from excess carbohydrates on their lipids as everyone else.
Protein
Protein is a critical component of all cells and is involved in practically every function performed by them. They are important in the structural framework of cells and tissues as well as the immune system and transporting oxygen. Although the body doesn’t store extra protein, the body can use existing protein as a source of energy if necessary. In a normal person, this is a done only as a last resort because of the protein loss disrupts normal functioning and can lead to death.Protein is normally broken down and the kidney helps remove toxic byproducts (including nitrogen and sulfur). In kidney failure, the toxins accumulate and lead to blood poisoning (called uremia). In addition, kidney disease can lead to inappropriate break down of the body’s protein thus leading to protein malnutrition (even when fats and carbohydrates are present in plenty). Also, some people with kidney disease lose a large amount of protein (in the form of albumin) in the urine.
Minerals
Minerals are nutrient substances that do not contain carbon (inorganic) and are chemically inactive by themselves. They are part of numerous substances that wouldn’t work well without them. They are particularly important for tissue structure, regulating body functions, as well as proper functioning of nerves and muscles.
- Electroytes: The kidney is responsible for keeping the major minerals in balance. With kidney failure, minerals can build up in the body and become very toxic and life-threatening. The major minerals that are called electrolytes include:
- Sodium (Na)
- Potassium (K)
- Chloride (Cl)
- Calcium (Ca)
- Magnesium (Mg)
- Phosphorus (P)
- Water: Your body is made up mostly of water and it is essential for life. Although you can go without food for weeks or months, you couldn’t survive long without fresh water. The kidney is responsible for conserving water when it is sparse and eliminating it when it is plenty. The kidney is able to do this through its ability to vary the concentration of water in the urine. Unfortunately, people with kidney disease can lose this ability and are prone to becoming dehydrated and fluid overloaded.
- Trace Elements: A number of other minerals are found in very small amounts. One of the most recognized is iron. People with kidney disease have a hard time absorbing iron which can (along with reduced hormone production by the kidneys) lead to low blood counts (or anemia). Trace elements can also be removed by dialysis as well.
Vitamins
Vitamins are nutrient substances that are made with carbon (organic) and function to regulate processes in the body. They cannot be made by the body and have to be obtained through diet or supplements. They are usually classified based on whether they dissolve better in water (water-soluble) or fat (fat-soluble). Most vitamins are converted into an active form after they have been absorbed from the diet.Vitamins are important in people with kidney failure because water-soluble vitamins are often removed by dialysis. Because the kidneys in people with kidney disease are often no longer able to activate Vitamin D (which is important in many bodily functions especially involving bone), they are often treated with Vitamin D medications.
Source
- Daignault et al. “Nutritional Requirements of Healthy Adults.” Handbook of Nutrition and the Kidney. Ed William Mitch and Saulo Klahr. Philidelphia: Lippincott Williams & Wilkins, 2005. 1-28.