Several nutrients play a significant role in maintaining the integrity and function of the immune system and act synergistically in determining the immune response. Zinc, Vitamin C, and D possess immunomodulatory functions and play a role in maintaining physical tissue barriers. These nutrients act in synergy to maintain physical tissue barriers such as skin and mucus membrane. 

Zinc is critical for the integrity of the immune system and has a vital role in maintaining, developing, and activating cells during innate and adaptive immune responses. It also plays a role in the integrity of epithelial barriers, important for organism defense and prevention of pathogen entry. Zinc is essential for the integrity and homeostasis of the intestinal barrier. 

Vitamin C or ascorbic acid is a micronutrient with antioxidant properties that plays an essential role in the immune system, supporting the epithelial barrier against the entry of pathogens and the cellular functions of the innate and adaptive immune systems. 

Vitamin D3 plays an important role in the body’s immune function. Vitamin D receptor is also present in pulmonary epithelial cells. Vitamin D also plays an essential role in the function and maintenance of epithelial and endothelial barriers, including lung tissue. 

Vitamin C, D, and zinc show synergistic functions at various stages of the host defenses, including maintaining the integrity of biological barriers and the functionality of cells constitutinginnate and adaptive immunity. 

Resources: Name JJ, Souza ACR, Rodrigues A, et al. Front. Nutr. 2020; DOI:10.3389/fnut.2020.606398