Zinc citrate is the salt made when zinc is combined with citric acid. Zinc picolinate is the salt made by combing zinc with picolinic acid. After iron, zinc is the second most abundant trace element in the body.
Zinc plays an important role in immune function, as well as in neurotransmitters, wound healing, growth, thyroid hormone function, insulin activity, and taste and smell. Zinc is a cofactor in the synthesis of DNA, RNA, and protein, and is found in more than 300 enzymes. For example, zinc is needed for the transport protein of vitamin A, and insufficient zinc levels can lead to vitamin A deficiency. Zinc is an essential metal cofactor for one kind of superoxide dismutase (SOD), a major class of antioxidant enzymes. Zinc is found in many foods, including red meat, poultry, seafood, dairy, nuts, legumes, and unrefined grains.