Nutrition is more of an issue for patients with advanced renal disease than for those still in the early stages. Many early-stage patients have no restrictions beyond following a sensible, low-sodium diet. For these patients, supplements are not needed. However, as the kidneys become less able to regulate blood levels of nutrients, issues with water soluble vitamins may emerge.
Definitions
Water soluble vitamins include all B vitamins and vitamin C. Vitamins A, D and E are not water soluble. The Colorado University State Extension says that since these water soluble vitamins are easily excreted, they need to be replaced every day.
Renal disease is another name for kidney disease. It includes kidney diseases caused by diabetes, hypertension, glomerular diseases, as well as congenital kidney disorders.
Nutritional Issues
Patients with advanced kidney disease have complex nutritional issues. They tend to lack many water soluble vitamins because many fruits, vegetables and dairy products are not allowed on the low potassium and low phosphorus diets that many patients must follow.
Vitamin D-3 levels in these patients tend to be low because the kidneys no longer convert vitamin D-2 to D-3. Vitamin A levels tend to be high because the kidneys do not effectively excrete this vitamin.
Vitamin Supplements
Nephrologists may prescribe multivitamins that are specially formulated to satisfy the needs of kidney patients. These multivitamins include the necessary water soluble vitamins. Regular multi-vitamins might be dangerous for kidney patients because they include vitamin A.
DaVita, a leading dialysis provider, recommends that kidney patients take no more than 60 mg to 100 mg of vitamin C because this vitamin "can cause a build up of oxalate, which can be deposited in the bones and soft tissues."
Warning
Never take supplements without consulting a nephrologist. In some instances, malnutrition is preferable to the consequences of taking a particular vitamin. For example, nephrologists may intentionally avoid treating vitamin D deficiencies because getting enough vitamin D-3 could exacerbate high phosphorus levels, which in turn cause high serum calcium.
