Which vitamin is directly associated with immune function and skin health?

Vitamin A plays a crucial role in maintaining immune function and skin health. It is essential for the growth and differentiation of epithelial cells, which make up the skin and mucosal barriers. Additionally, vitamin A is involved in producing antibodies and is important for the proper functioning of T-cells, a type of white blood cell that is pivotal for immune response. Deficiencies in this vitamin can lead to increased susceptibility to infections and impaired wound healing, highlighting its importance in both immune health and skin integrity.

In contrast, other vitamins listed, while also important for various bodily functions, do not have the same direct connection to skin health and immune function as vitamin A. Vitamin D is predominantly associated with bone health and calcium regulation, vitamin E is primarily an antioxidant that protects cell membranes from oxidative damage, and vitamin K is crucial for blood clotting and bone metabolism. Each vitamin has its specific roles, but when it comes to immune function and skin health, vitamin A stands out as the most directly involved.