Zinc, a nutrient found throughout your body, helps your immune system and metabolism function. Zinc is also important to wound healing and your sense of taste and smell.

With a varied diet, your body usually gets enough zinc. Food sources of zinc include chicken, red meat and fortified breakfast cereals.

People use zinc supplementation for:

>Colds. Evidence suggests that if zinc lozenges or syrup is taken within 24 hours after cold symptoms start, the supplement can help shorten the length of colds.

>Wound healing. People with skin ulcers and low levels of zinc might benefit from oral zinc supplements.

>Diarrhea. Oral zinc supplements can reduce the symptoms of diarrhea in children with low levels of zinc, such as from malnutrition. There isn't enough evidence to recommend use of oral zinc for children with diarrhea who have a healthy, varied diet.

>Age-related macular degeneration. Research suggests that oral zinc might slow the progression of this eye disease.