You may have heard of selenium and zinc, but how exactly do they benefit you? The body contains small amounts of both, and they play a vital role in your health. Selenium is classified as an ultra-trace element that has one essential role, while zinc is known as a trace element that has various functions throughout the body. Interestingly, deficiencies of selenium and zinc are rare in the United States due to fortification of products and high intake of animal meats.
The primary function of selenium is to make antioxidant enzymes that protect your cells from damage caused by harmful free radicals. More specifically, selenium converts harmful hydrogen peroxide to water in your cells to prevent any damage. Additionally, selenium helps strengthen your body's immune system after you receive a vaccination and also supports thyroid health.
Selenium Food Sources
The recommended daily allowance for selenium is 55 micrograms per day for healthy adults. The amount of selenium in food is dependent on the soil in which it was grown. Common food sources include Brazil nuts, halibut, tuna, oysters, chicken, egg noodles, lobster, sunflower seed and eggs. The content of selenium in grains varies based on the soil, and fruits and vegetables have limited amounts of selenium. The typical American diet contains enough selenium to prevent a deficiency and maintain health.
Zinc collaborates with over 300 enzymes that start essential reactions in your body, such as digestion of food. This trace element helps maintain healthy brain cells, transports essential compounds throughout the body, aids in immune function, stabilizes your gene structure and helps form your bones.
Zinc sulfate is commonly used to treat the common cold. In adults, supplementation reduces the severity and duration of symptoms. However, more research needs to be conducted to determine if it decreases the frequency of the common cold.
Zinc Food Sources
The main food sources of zinc are meat, fish, poultry, ready-to-eat breakfast cereals, milk and other dairy products. Other good sources include oysters, dry beans, nuts, peas and wild rice. The daily reference intake for adult women is 8 milligrams per day. The majority of Americans consume 10 to 15 milligrams per day.
Selenium and Zinc
All vitamins and minerals intricately work together to aid in health and disease. For instance, selenium and vitamin E function together by protecting your body from inflammation, which is correlated to certain diseases. Scientific research continues to try and determine the effects of selenium and vitamin E on cancer, if there are any. Zinc also helps your immune system fight to maintain health. Thus, when you eat a variety of nutrient-dense foods, your body is equipped to stay strong and healthy.
- Krause's Food & Nutrition Therapy; L. Kathleen Mahan, Sylvia Escott-Stump
- IUBMB Life: Selenium-containing Amino Acids as Direct and Indirect Antioxidants
- American Family Physician: Treatment of the Common Cold
- The Journal of the American Medical Association: Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)
- Toxicology and Industrial Health: Dimethoate-induced Oxidative Damage in Erythrocytes of Female Adult Rats
Laura Michele Oliver received her bachelor's degree in nutrition from Auburn University. She served as a dietetic intern at Rush University Medical Center in Chicago, where she also graduated with a Master of Science in clinical nutrition. She now works as a registered dietitian in Brooklyn, N.Y.