Final answer:
In celiac disease, malabsorption of nutrients occurs due to damage to the microvilli in the small intestine caused by an immune response to gluten, resulting in various health complications.
Step-by-step explanation:
In celiac disease, the body's immune response to gluten, found in wheat, barley, and rye, damages the microvilli which are fingerlike projections in the small intestine specializing in nutrient absorption. This leads to malabsorption of nutrients, which can cause a wide variety of symptoms including diarrhea, anemia, osteoporosis, skin rashes, and other health issues. Malabsorption in celiac disease can result in long-term complications such as damage to the nervous and reproductive systems, and increased risk of certain cancers. To manage the condition, individuals with celiac disease must maintain a strict gluten-free diet, which can alleviate the symptoms and reduce the risk of further complications.