Vitamin Toxicity In Patients With Liver & Kidney Disease

Vitamins serve a variety of functions and are essential for the development of strong, healthy bodies. The recommended daily allowances and upper limits have been determined and are listed by the National Institutes of Health, or NIH. Some vitamins can be toxic if consumed at a high amount; this is especially true if you have liver or kidney disease.

About Vitamins

Vitamins are only needed in small amounts, and yet they are absolutely essential. They serve as antioxidants and are involved in many functions including vision; the maintenance of healthy skin and bones; the breakdown of carbohydrates and glucose to provide energy for the cells; the production of hormones, cholesterol, red blood cells, DNA, glucose and the myelin that covers the nerves; the metabolism of fatty acids and amino acids; the support of the immune system; and the formation of blood clots.

The NIH lists the recommended daily requirements so you know how much is needed for good health. Some vitamins are toxic when taken in high doses, namely vitamins A, B-3, B-6, C, D, E and K. Taking the recommended amount of vitamins is not toxic, even if you have a liver or kidney disease. High doses of vitamin A, niacin and vitamin D are especially toxic in these diseases.

Vitamin A

Your eyes use vitamin A to make rhodopsin, a red pigment located in the retina of the eye that is needed so you can see in dim light. This vitamin also helps the immune system, develops and maintains healthy skin and bones and maintains the mucous membrane that lines the intestines, urinary and respiratory tracts. Women 19 years old and older should have 700 mcg a day, while men should have 900 mcg daily. Taking a high amount of vitamin A can cause toxicity, causing nausea, vomiting, headaches, dry eyes and skin, dizziness and hair loss. Taking too much over a period of time can be harmful to the liver, causing cirrhosis and obstruction in the veins. The risk of liver damage will be increased if you have liver disease or kidney disease.

Niacin

The cells use enzymes to speed up a biochemical reaction and sometimes must use coenzymes to help. Two coenzyme forms of niacin, which is vitamin B-3, must be used to change food into energy. The recommended amount is 14 mg a day for females 14 years old and older and 16 mg a day for males. Taking this vitamin in high amounts in the immediate-release and sustained-release forms will lower your low-density lipoprotein cholesterol and triglyceride levels and raise your high-density lipoprotein cholesterol level. It is rare, but high doses of niacin can be harmful to the liver and may occur more often with the sustained-release form, so someone with liver disease should not take niacin in high doses.

Vitamin D

When the calcium level in the bloodstream falls low, the parathyroid gland sends a hormone to the bones and kidneys, triggering them to raise it. The kidneys do this is by changing the inactive form of vitamin D to the active form, which will then instruct the intestines to absorb more calcium. Vitamin D is, therefore, needed to maintain the proper calcium level, a mineral required for healthy bones, muscle contractions and the signaling between nerves. The recommended daily allowance is 600 IU for those 19 to 70 years of age and 800 IU for those 71 years and older. A toxic level of vitamin D will cause a high level of calcium and its associated symptoms of nausea, constipation, abdominal pain and excessive urination. It can also cause kidney damage and even kidney failure.