Zinc + Vitamin C Plus Histidine

Contributes to the normal functions of the immune system 
For maintenance of normal healthy skin, hair and nails

Vitamin C is a water-soluble vitamin that comes from diet, it cannot be synthesized by the body, nor does the body store it. Vitamin C helps the body form collagen, which is the main protein used as connective tissue in the body, in blood vessels, bones, cartilage, gums, skin and teeth. Zinc also contributes to the maintenance of normal hair, nails and skin.
Zinc and vitamin C support the normal function of the immune system and help to protect cells from oxidative stress. 

L-histidine is an essential amino acid, it is involved in the formation of proteins and influences several of the metabolic reactions in the body. As L-histidine is only produced in very small amounts by the body, it must predominantly be taken  through diet or a food supplement.