Malabsorption is common in chronic alcoholics. Alcoholics may malabsorb fat, nitrogen, sodium, water, thiamine, folic acid, vitamin B12, and D-xylose. Malabsorption is due to an abnormal luminal phase of digestion as well as a diffuse functional mucosal abnormality.
Malabsorption may therefore contribute to clinically significant malnutrition, diarrhea, folate deficiency, and abnormalities in tests of xylose and vitamin B12 absorption. Factors causing malabsorption in alcoholics include folic acid and protein deficiencies in the diet, pancreatic insufficiency, biliary secretion abnormalities, and direct effects of alcohol on the gastrointestinal tract.
Many of the absorption abnormalities are reversed when alcoholics are fed a nutritious diet, even if they continue to consume alcohol. This underscores the causal role of nutritional deficiencies in the malabsorption of chronic alcoholics.
Clin Gastroenterol: Alcohol, Nutrition and Malabsorption
Found at Alkohol adé (german)