Zinc is a trace element our body needs in small amounts. Zinc is important for many biological processes in the body, and has many amazing benefits! It is an important factor for a healthy immune system, it aids in DNA production, cellular growth, protein synthesis, and repairing damaged cells and tissue!
Because zinc plays such an important role in cellular growth, children, adolescents, and pregnant women must have adequate zinc intake for healthy growth!
Benefits of Zinc
Immune Health
Over the years many studies have shown how important zinc is for the immune system. Zinc is needed for the development and function of cells like neutrophils, and natural killer (NK) cells. These are cells of the immune system that help fight off pathogens and bacteria in the body. Individuals with low zinc levels have been shown to have lower amounts of T and B cells which are important for fighting infections and creating antibodies.
DNA Production
There are over 100 enzymes in the body that need zinc to carry out their functions, and these enzymes are used in major metabolic processes. Zinc helps in DNA and protein synthesis as zinc is found in all parts of the cell during production and it also helps stabilize the structure of DNA. Zinc is also needed for several enzymes important for DNA and protein synthesis!
Wound Healing
Wound healing is an important physiological response by the body when there has been damage to the tissues. Skin contains quite a high percentage of our total body zinc content ~5%, and low zinc levels have been shown to impair wound healing. When tissues are damaged there are a lot of processes that take place during wound healing, and zinc is needed at every step. Zinc helps with clot formation, inflammation, fighting infections, new cellular growth, and scar formation.
Antioxidant effects
Through natural metabolic processes, our body produces these products called free radicals, these products can cause damage to our cells and genetic material. When free radicals are in the body, they can disturb other substances around them by “stealing” their electrons, which can alter that substance's function and shape. When there are excessive amounts of free radicals this can lead to a condition called oxidative stress which can further damage the cells and lead to chronic diseases.
Thankfully, there is a defense mechanism against free radicals, they are called “antioxidants”. There are hundreds of substances that can act as antioxidants, and examples include vitamin C, Vitamin E, and beta carotenes. Zinc also has antioxidant effects! Several studies have shown that oxidative stress can increase with zinc deficiency.
Common Cold
As zinc plays an important role in the immune system studies have shown that taking zinc lozenges while battling a cold can help reduce the duration of sickness. However, higher-quality studies need to be done to understand zinc's role in preventing a cold.
Zinc in the body
After consuming food containing zinc, it will be absorbed in the small intestine and stored in different parts of the body. ~60% is found in skeletal muscles, about 30% in our bones, 5% in our skin and liver, and 2-3% in other organs.
Recommended intake for Zinc
As zinc has many roles in the body when someone is zinc-deficient this can affect multiple organ systems and tissues, so it is important to get a daily intake of zinc! The recommended dietary allowance (RDA) and Tolerable Upper intake (UL) for zinc in milligrams are as follows:
Age | RDA | UL |
0-6 months | 2mg | 4mg |
7-12 months | 3mg | 5mg |
1-3 years | 3mg | 7mg |
4-8 years | 5mg | 12mg |
9-13 years | 8mg | 23mg |
14-18 years | 11mg (male), 9mg (female) | 34mg |
19yrs and older | 11mg (male), 8mg (female) | 40mg |
Sources of Zinc:
Food
The most common way to get zinc is through food! The richest food source is meat, poultry, and seafood. Oysters actually contain more zinc than any other food! Foods like beans, legumes, and nuts also contain zinc, however, the phytates present in these foods can inhibit zinc absorption, making it less available to the body for use.
Food sources of zinc:
Oysters
Crab
Beef
Fortified breakfast cereals
Nuts and seeds ( pumpkin, peanuts)
Dairy products (cheese, milk, greek yogurt)
Salmon
Kidney beans, lentils
Supplementation
Another form of zinc consumption is through supplementation with pills or lozenges, however high amounts of zinc can cause side effects such as nausea and vomiting and can inhibit the absorption of iron and copper. You should not have to take zinc supplements unless it is known your diet is low in zinc or you are zinc deficient. You can make an appointment with one of our dietitians to determine if you need a zinc supplement!
Zinc Deficiency
When an individual is zinc deficient this can impair growth, immune health, digestive systems, and protein synthesis. However, zinc deficiency is not common in the average healthy individual. Certain groups are more at risk than others, this includes
Gastrointestinal surgery: those who have undergone gastrointestinal surgeries, or who have digestive disorders are at higher risk for zinc deficiency due to lower amounts of zinc absorption
Vegetarians/Vegan: Those who follow a vegetarian or vegan diet get their zinc from plant-based foods which have a lower absorption rate than meat and seafood products.
Pregnancy and breast/chestfeeding: Pregnant and lactating people need more zinc to support their baby's growth and development
Elderly: Elderly people could be at higher risk of zinc deficiency due to malnutrition and low food intake.
Symptoms of Zinc deficiency
Infants and Children: Common symptoms in infants and children are diarrhea, stunted growth, and decreased appetite.
Older Adults: Zinc deficiency can cause impaired wound healing, and cognitive problems (thinking, memory, reasoning).
During Pregnancy: Zinc deficiency during pregnancy can cause preterm birth and low birth weight.
Too Much Zinc
Although it is important to incorporate zinc-containing foods into the diet, too much zinc can be harmful. Too much zinc is usually caused by supplementation, not through food intake. Toxic levels of zinc can cause the following symptoms:
nausea
vomiting
dizziness
loss of appetite
abdominal pain
headaches
Taking too much zinc over a prolonged period can interfere with the absorption of:
copper
iron
magnesium
Summary
Zinc has amazing benefits for the body, it plays a key role in child development, aids in DNA and protein synthesis, helps keep a healthy immune system, and contributes to wound healing and repairing damaged cells. Eating a balanced diet with different sources of vitamins, minerals, fiber, protein, and carbohydrates should provide you with a healthy amount of daily zinc intake!
Work Cited
Lin, P. H., Sermersheim, M., Li, H., Lee, P. H., Steinberg, S. M., & Ma, J. (2017). Zinc in wound healing modulation. Nutrients, 10(1), 16. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5793244/#:~:text=Zinc%20is%20a%20cofactor%20for,function%20and%20compromised%20would%20healing.
National Institutes of Health (2023). "Zinc". Office of dietary supplements. Available from: https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/#:~:text=The%20richest%20food%20sources%20of,also%20contain%20zinc%20%5B3%5D.
Prasad, A. S. (2014). Zinc is an antioxidant and anti-inflammatory agent: its role in human health. Frontiers in nutrition, 1, 14. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4429650/