Zinc deficiency
Zinc deficiency can occur in soil, plants, and animals. In animals, including humans, it is defined either qualitatively as insufficient zinc to meet the needs of the body and thereby causing clinical manifestations, or quantitatively as a serum zinc level below the normal range; however, serum zinc is not a reliable biomarker for zinc status in humans. Zinc deficiency affects about 2.2 billion people around the world.