Zinc & Immune Function: How Does it Help Keep Infections at Bay?

You might have heard about iron, calcium, or vitamin D deficiency, but how often have you heard about zinc deficiency? Zinc deficiency is a less popular mineral deficiency that is pretty common among the masses. Zinc is a trace mineral needed in small amounts but plays a big role in the healthy functioning of our body. The functions of zinc in the body range from building proteins, activating enzymes, repairing damaged tissues, making DNA, and growing cells to boosting immunity. The role of zinc in immune function is of great significance. 

Our surroundings are full of various pathogens that can harm our health. Fortunately, we have our immune system, which is like our body’s own defense force, to protect us. Our immune cells need zinc for their growth and normal functioning. A deficiency of zinc may slow down the activity of different immune cells like macrophages, lymphocytes, and neutrophils, which are responsible for providing protection against harmful pathogens. Let’s get to know a little more about zinc and its role in immune function through this article. 

What is Zinc? 

We need macronutrients (carbs, proteins, and fats) in greater amounts and micronutrients (vitamins and minerals) in lesser amounts from food for our survival, growth, and protection. Zinc is one of the trace minerals that is required in minimal amounts but has a profound function in the human body. Its role in the functioning of the immune system is of prime importance. Mostly stored in the muscles and bones, this micromineral is present in almost all cells throughout the body. However, zinc cannot be produced inside the body and should be obtained through diet or zinc supplements. 

Role of Zinc in Immune System 

Zinc plays a role in both innate and adaptive immunity and also helps primary organs of the immune system fight off infections. 

• Role of Zinc in Innate Immunity 

Zinc plays an important role in innate immunity (the body’s first line of fast defense against nonspecific pathogens). The skin and epithelial cells that serve as a barrier for invading pathogens require zinc for optimal functioning. Immune cells such as mast cells and dendritic cells residing at this barrier are also regulated by the mineral zinc. Thus, zinc helps the skin cells and cells lining the internal organs to prevent the invasion of pathogens.  

Zinc also helps the white blood cells called macrophages function optimally. These macrophages gulp down pathogens and also trigger signals to other immune cells for a counterattack. 

• Role of Zinc in Adaptive Immunity 

 Zinc also has a role to play in adaptive immunity (the one that uses the memory of a pathogen encountered previously) to launch pathogen-specific attacks with the help of T cells and antibodies. The activity of immune cells such as T cells, B cells, monocytes, and neutrophils in the blood is controlled by zinc. 

Zinc concentrations are tightly controlled by certain bodily mechanisms. For instance, when our body encounters any infection-causing pathogen, the immune cells, namely macrophages, secrete a class of proteins called ZIP8. These proteins regulate the entry of zinc inside the cells and the production of defense molecules like cytokines. 

• Role of Zinc in Immunological Organs 

The thymus and bone marrow are two primary organs where immune cells mature, develop, and grow. Both of these organs require zinc for functioning. Thus, zinc is responsible for the development of immune cells and the optimal functioning of the thymus and bone marrow. 

Groups at Risk for Deficiency 

Growth phases such as childhood, adolescence, and pregnancy are the stages where zinc requirements increase the most, as zinc is needed for the growth of cells. Senior citizens are also at risk of zinc deficiency, as the body’s ability to absorb this mineral decreases with age. 

• People with digestive disorders such as IBD, Crohn’s disease, or ulcerative colitis 
• Vegetarians or vegans 
• Pregnant or breastfeeding women 
• People who suffer from chronic conditions like diabetes, sickle cell disease, liver disease, and kidney disease.
• Alcoholic 

Signs of Zinc Deficiency 

The only way to confirm zinc deficiency is by measuring serum levels of zinc. However, the plasma levels of zinc may not be very precise, or accurate. Serum zinc levels may fluctuate depending on medical conditions, phases of people's lives, and hormonal fluctuations. However, some common signs of zinc deficiency include: 

• Decreased Immunity 
• Loss of appetite 
• Slow wound healing 
• Hair loss 
• Depression 
• Loss of sensations (taste and smell) 
• Diarrhea 

Sources of Zinc 

One of the best sources of zinc is oysters, but it is also present in other seafood, poultry, dairy, and plant-based foods. Listed below are a few of the most common sources: 

• Oysters 
• Beef roast 
• Crab 
• Lobster 
• Pumpkin seeds 
• Whole Grains 
• Beans 

Zinc in Supplements 

Zinc benefits us in many ways. However, excessive zinc intake over a long period of time may lead to toxicity and copper deficiency by reducing copper absorption in the gut. Both zinc deficiency and overdose can impair immune function. An effective way to ensure optimal zinc intake would be through the ingestion of zinc supplements. Especially if you are vegetarian or vegan, chances are you may not be getting enough zinc through your diet alone. Market shelves are flooded with zinc supplements like zinc tablets, capsules, gummies, effervescent, etc. The best zinc supplement would be one combined with vitamin C. Vitamin C is yet another essential element that will greatly enhance your immune function. Vitamin C and zinc tablets act as double boosters for the immune system. 

Wrapping Up 

Zinc's functions in the human body are numerous. It plays a vital role in boosting your immune system and fighting off infections. You may not be getting your daily dose of zinc due to unhealthy eating practices, digestive disorders, veganism, etc. This increases susceptibility to various kinds of illnesses. Ensuring adequate zinc intake through diet, supplements, or both can help build immunity and decrease your chances of falling ill frequently. 

References 

https://www.hindawi.com/journals/jir/2016/6762343/ 

https://www.fredhutch.org/en/news/center-news/2022/03/dudakov-zinc-thymus-regeneration.html 

https://link.springer.com/chapter/10.1007/978-3-030-16073-9_8 

https://www.mdpi.com/2072-6643/9/12/1286 

https://knowablemagazine.org/article/health-disease/2021/how-zinc-helps-fight-infections