People who are addicted to alcohol may become severely deficient in important basic vitamins and minerals, directly affecting their health. Individuals who consume more than 30 percent of their calories as alcohol have the greatest risk, particularly for deficiencies in thiamine and vitamin A. Supplements can often help, but the best choice is treatment for alcoholism.
Some alcoholics develop a thiamine (vitamin B1) deficiency, which can lead to an alcoholic brain disease known as Wernicke-Korsakoff syndrome (WKS). A thiamine deficiency caused by malnutrition is rare in developed countries, but does occur among alcoholics. According to Peter R. Martin and colleagues in their article for the National Institute on Alcohol Abuse and Alcoholism about thiamine deficiency in alcoholic brain disease, autopsy studies have shown brain abnormalities resembling WKS in 13 percent of alcoholics.
Wernicke's encephalopathy is the first part of WKS and it causes confusion, paralysis of eye nerves and difficulty with movement. Up to 90 percent of those with Wernicke's encephalopathy develop Korsakoff's psychosis, which causes memory deficits and abnormal behavior. If WKS is diagnosed before severe deterioration occurs, taking oral or injected thiamine may reverse it.
Alcoholics may be deficient in vitamin A. As a result, an individual may develop fatty liver, a stage of alcoholic liver disease. If liver disease progresses, the person may develop liver cirrhosis and need a liver transplant to survive. Supplementation with vitamin A supplements generally is not recommended unless the alcoholic actively commits to stop drinking, because the combination of vitamin A and alcohol can be toxic.
Alcoholics may be deficient in important minerals, including iron, calcium and zinc. Low levels of iron can cause anemia. A calcium deficiency (hypocalcemia) can cause bone disease, while insufficient levels of zinc can lead to skin lesions as well as night blindness.