Zinc Essential for Immunity, Sense of Smell, and More

May 4, 2020 | Dr. Linda J. Dobberstein, DC, Board Certified in Clinical Nutrition


When it comes to your health, your body needs all kinds of nutrients ranging from vitamin A to Zinc. Zinc is the second most abundant trace mineral stored in the body. Your body requires this essential mineral literally for thousands of functions, rendering a high need for adequate and optimal tissue levels. Estimates show that at least one out of four individuals across the globe or nearly two billion individuals are at risk for zinc deficiency. Are you one of them?


Zinc is Biologically Essential for Immune Function


A little extra zinc for immune support is a popular method of self-care with good reason. Immune cells deeply depend upon adequate zinc to work. Zinc acts like a gate keeper for your immune system’s biological activity. The presence of adequate zinc literally turns-on numerous functions with your immune system.


Inside cells, zinc binds with proteins which enhances its metabolic effects. This impacts oxidative stress management, cell signaling and clean-up, cell structure and cell membranes, detoxification of heavy metals, immune activity responses and management of germs, along with white blood cell production and functions. Zinc is on the front lines of immune homeostasis and defense.


Zinc Crucial for Whole Body


Zinc is involved with other functions throughout the body. For example, energy production, heart rate and rhythm, gastrointestinal function, gut barrier integrity, stomach acid production, brain and cognitive function, skin health and integrity, nerves and muscles all require adequate zinc.


Zinc is involved with blood sugar, blood pressure, LDL cholesterol, and heart health. Zinc directly impacts leptin and thyroid function, adrenal health, fertility, and reproduction.


Zinc is needed for growth and development and is especially needed during infancy through puberty. Zinc is biologically essential for gene transcription, DNA synthesis and RNA transcription. It plays essential roles in major antioxidant systems like SOD, glutathione, and Nrf2.


Smell and Taste and Other Senses


Your sense of smell and taste relies on zinc. When you smell something, that scent is received by a group of nerves called the olfactory bulb. These nerves are located deep in your upper nasal passages and transmit signals to the hippocampus. The hippocampus plays a major role in memory and learning and is part of the limbic system located deep in the brain.


Smells are powerful memory triggers because of interactions between the olfactory bulb, and hippocampus. For example, the smell of fresh baked oatmeal cookies makes you think of your grandmother’s kitchen or a certain brand of cologne makes you think of your dad. This is in part due to how the olfactory bulb and hippocampus “talk to each other” with nerve signals. Your olfactory bulb and hippocampus require zinc for these functions and nerve transmissions.


Your body needs zinc for your other special senses. Your eyes, especially the retinal tissues, have a very high need for zinc. Your ears need zinc for hearing. Age-related decline in vision and hearing have been linked with diminished zinc levels. Zinc even helps your nerves with the sensation of touch.


Oral and Dental Health


Zinc helps maintain oral health. It helps your mouth flora with management of tartar and the yellow plaque that builds on teeth. Zinc is required to maintain strong mineralization in teeth.


Zinc and Other Nutrients


Chronic high dose zinc intake by itself can deplete other minerals like copper, magnesium, calcium, and iron out of your body. A multiple mineral supplement can help offset these mineral imbalances. Zinc and copper work best in balance. For supplementation, an optimal ratio of zinc to copper is 8:1 or 10:1.


A lack of zinc, however, can mimic iron deficiency symptoms. Studies show that when individuals fail to respond to iron supplementation, it may be due to inadequate tissue levels of zinc. In addition, zinc is essential for vitamin A function in your body.


Zinc Sources and Needs


Oysters provide the richest content of zinc, followed by red meat, crab, lobster, and poultry sources. Small amounts of zinc (0.5 -2.9 mg per serving) are found in pumpkin seeds, beans, peas, fortified cereal, dairy, and other seeds and nuts. Zinc from plant-based foods is not as absorbable compared to animal-based foods.


The minimum recommended daily intake for men is 11 mg and for women is 8 mg. Higher doses of 25 - 75 mg or more may be needed to replenish zinc. Once your body lacks adequate zinc, it may take 6-24 months of diligent support to replenish zinc stores.


Increased immune needs, stress, gut inflammation, poor digestive absorption, heavy sweating and perspiration, growth, puberty, and reproduction increase zinc requirements. Individuals with chronic immune challenges, liver disorders, and gastric bypass are also more likely to lack zinc. Insufficient zinc intake commonly occurs in the elderly and individuals who have adopted a vegan/vegetarian/plant-based diet.


Medications and Zinc


Numerous medications deplete zinc from the body. Some of the more common medications that rob zinc include some blood pressure medications, aspirin, cholestyramine (cholesterol lowering), benzodiazepines, birth control, diuretics, antiseizure and neuropathy medications, and several others. Check with your pharmacist to see if your medication contributes to zinc deficits in your body.


“Feet stink? Need zinc!” is an adage in clinical nutrition reflecting the connection of body odor and lack of zinc. In light of this information, you can also potentially attribute other changes in smell and taste, hearing, vision, touch, loss of immune vigor, and dental tartar, etc. to needing additional zinc in your dietary arsenal. Zinc is the second most needed trace mineral in the body. Iron is the first. Today’s challenges require optimal zinc levels. How you are doing?