Final answer:
Alcohol can damage the digestive system, particularly the small intestine, reducing the absorption of both water-soluble and fat-soluble vitamins, which can result in vitamin deficiencies.
Step-by-step explanation:
Alcohol consumption can negatively affect vitamin absorption in the human body. Chronic alcohol intake has been shown to hinder the absorption of vitamins by damaging the lining of the digestive system, particularly the small intestine where nutrient absorption primarily occurs. For example, alcohol can interfere with the absorption of water-soluble vitamins such as the B vitamins and vitamin C, which are absorbed with water in the gastrointestinal tract. Excessive alcohol consumption can also lead to a depletion of these vitamins since they are not stored in the body and any excess is excreted in urine. Furthermore, alcohol hastens the excretion of fat-soluble vitamins A, D, E, and K through the liver, which could result in deficiencies despite adequate intake. It's important to note that the effect of alcohol on vitamin absorption may vary based on an individual's overall health, diet, and level of alcohol consumption.