Searching for the fountain of youth has been going on since the first gray hair made its appearance. Although gray hair can appear at any age, it is often one of the first signs of aging, and many products have been developed to prevent or mask them. It is rumored that zinc can help restore a person's natural color.

Zinc is an element present in the human body with largest concentrations found in the hair, bones, muscle and skin. Zinc also is found in enzymes, where it plays a pivotal role in many metabolic processes. It is required for normal physical development and reproductive health and it supports the immune system as well. Although zinc is found in the body, it is not stored and your body requires dietary intake to meet its daily needs.

A study described in the “Federation of American Societies for Experimental Biology” journal revealed that a buildup of hydrogen peroxide disrupts melanin in the hair shaft and throughout the body, causing gray hair. Melanin is what gives our hair its color and our skin its pigmentation. Smoking also has been found to influence early graying, and genetics plays a significant role in determining when gray hair appears. Zinc does not appear to play a significant role in hair color.

According to the “Biological Trace Element Research” journal, a study was conducted to determine the level of trace elements in human hair. Though this study did not focus on the causes of graying in hair, it did reveal that all colors of hair contain levels of zinc. Brown hair contained more zinc than light blond hair, but the difference was slight. Very dark brown or black hair had the highest concentrations of zinc. Copper also is found in hair, and it was noted that as the study subjects got older, the copper content decreased in brown and blond hair. There was no change in zinc concentrations.

While there is no definitive evidence that zinc directly impacts hair color, there might be benefits to using zinc on your hair. The “British Journal of Dermatology” released a study that showed promising results on the use of zinc shampoo for thinning hair. The shampoo not only significantly increased the numbers of hairs, it also slightly increased the thickness. It is important to note that test subjects in that study used zinc shampoo topically and did not ingest zinc internally.

The human body requires a daily intake of zinc to maintain normal processes and, in children, it aids in their development. The recommended daily intake is 12 to 15 mg for adolescents and adults. These values differ by age and if you are pregnant or breastfeeding. Supplementation of additional zinc above the recommended intake should be done with caution. An overdose of zinc can cause dizziness, fainting, stomach upset, chest pain and vomiting.