What deficiency might require supplementation in a patient with celiac disease?

In a patient with celiac disease, there is a high likelihood of malabsorption due to damage to the small intestine's villi caused by gluten ingestion. This malabsorption can lead to deficiencies in various nutrients, particularly fat-soluble vitamins such as vitamin D.

Vitamin D is important for calcium absorption and maintaining bone health, and its deficiency can lead to osteopenia or osteoporosis, conditions that individuals with celiac disease are at increased risk for due to malabsorption. Therefore, vitamin D supplementation is often necessary in these patients to prevent or treat deficiency and its associated complications.

While deficits in other vitamins can occur in celiac disease, vitamin B12 deficiency is more commonly related to gastrointestinal conditions that affect the terminal ileum, such as Crohn's disease, rather than celiac disease specifically. Vitamin K deficiency is less common because it can be produced by intestinal bacteria, and vitamin C is water-soluble and usually not affected as drastically by celiac disease as fat-soluble vitamins. Thus, the need for vitamin D supplementation is particularly relevant for celiac disease patients due to their increased risk for malabsorption of fats and fat-soluble vitamins.