Zinc plays an important role in regulating how the immune system functions. It is critical in helping the immune system fight off bacteria and viruses.

Zinc also helps to limit the level of inflammation produced during an active infection.

One recent medical study has demonstrated that an inadequate amount of zinc promotes chronic inflammation and may be crucial in the liver damage in people infected with hepatitis C.

Hepatitis C is caused by the hepatitis C virus. The illness may last a few weeks or can become chronic. The most common mode of transmission is through blood and blood products.

About 70 million people worldwide are chronically infected with hepatitis C and many of these will go on to develop cirrhosis of the liver and or liver cancer.

Although antiviral medications can cure more than 95 percent of patients with chronic hepatitis, these medications are very expensive and their availability worldwide is quite limited.

Interestingly, some studies have demonstrated that up to 45 percent of people infected with hepatitis C will experience a spontaneous cure. Might this be related to the amount of zinc in their diet? The answer is unknown.

Zinc is a mineral that is critical for our health and yet, worldwide, over 2 billion people are zinc deficient. Most commonly zinc deficiency is a result of inadequate dietary intake.

Some diseases of the bowel may also result in poor absorption or increased loss of zinc. Much of our zinc comes from meat, but our vegetables are also an important source.

A large portion of the earth's soil is zinc deficient. Therefore the vegetables that grow there and the animals that eat the vegetables can also be lower in zinc. Therefore zinc deficiency or at least insufficiency is relatively common.

Zinc plays a vital role in the proper functioning of many organ systems including the bowels, the brain, the immune system, the bones and the skin.

Zinc insufficiencies or deficiencies are risk factors for diarrhea, pneumonia, malaria, as well as an increased risk of death.

Zinc's effect on reducing the damage from the chronic liver inflammation associated with hepatitis C was published this year in the science journal Nature Communications. This publication demonstrated that zinc was critical for limiting the destructive inflammation of the liver without altering the ability of the immune system to fight the hepatitis C virus.

Zinc significantly reduced the ability of a specific type of interferon, IFN-3, to promote the chronic inflammation that is the hallmark of hepatitis C infection. The authors suggested that zinc insufficiency contributes to the severity of liver damage and possibly increases the risk of liver cancer in those with chronic hepatitis C infections.

Zinc can be taken as a supplement and is often added to multivitamins. The optimal daily amount of zinc for hepatitis C infection is unknown and blood tests for zinc are inaccurate at determining the zinc tissue level, so eating zinc-rich food is important.

There are many foods that contain zinc and a good resource is found on the National Institute of Health website: https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/.

• Patrick B. Massey, MD, PH.D., is medical director for complementary and alternative medicine at Alexian Brothers Hospital Network and president of ALT-MED Medical and Physical Therapy, 1544 Nerge Road, Elk Grove Village. His website is www.alt-med.org.