Which of the following is most likely affected by coeliac disease?

Coeliac disease is an autoimmune condition where the ingestion of gluten leads to damage in the small intestine. This damage can significantly affect nutrient absorption, which in turn has a wide range of implications for overall health.

Bone density is often compromised in individuals with coeliac disease due to malabsorption of calcium and vitamin D, essential nutrients for bone health. This increases the risk of osteoporosis and fractures.

Muscle mass can also be affected because when the body is not absorbing nutrients properly, protein synthesis may be impaired. This could lead to muscle wasting or difficulty in gaining muscle mass, particularly if dietary intake is not meeting the increased nutrient needs.

Skin health can be influenced due to the autoimmune nature of coeliac disease, which may manifest in dermatitis herpetiformis, a skin rash that occurs in some individuals with the condition. Moreover, nutritional deficiencies that stem from malabsorption can impact skin integrity and health.

Since all these factors—bone density, muscle mass, and skin health—can be affected by the malabsorption and autoimmune reactions associated with coeliac disease, the most comprehensive answer reflects the multifaceted ways in which the disease can impact a person's health.