Zinc: Deficiency, Sources, Benefits, Dosage & Side Effects

by Meenakshi Nagdeve last updated - Medically reviewed by Zemira Barnes (MS)

The health benefits of zinc include a healthy immune system and improved metabolism. It helps in wound healing, treating the common cold, and reducing the severity of diarrhea in children. Zinc also makes for a crucial nutrient in delaying age-related health conditions like macular degeneration and arthritis. Including it in your diet helps fight acne and many other skin conditions.

What is Zinc?

Zinc is an essential mineral, which is required by your body in trace amounts. It is important for a healthy immune system and protein synthesis. Zinc is also important for the growth and development of the body. A lack of zinc may lead to many conditions like diarrhea in children, stunted growth, and slow wound healing. [1]

The human body cannot produce zinc, and it cannot store it in excess quantities, which makes it an important part of a daily diet.

What is the Importance of Zinc?

Zinc plays a vital role in protein synthesis, cell signaling/neurotransmission, vision, and helps regulate cell production in the immune system of the human body. It is also important for two of the most important senses like taste and smell. In the human body, there are more than 300 different enzymes that require zinc to function normally. Researchers believe that 3,000 proteins (out of approximately 100,000) have this vital mineral. [2]

A normal person has two to three grams of zinc at any given time. It is used up in various metabolic processes and eliminated through normal excretory and urinary channels, so it needs to be replenished often. If it isn’t, you will begin to suffer from deficiency symptoms, a list of which can be found below.

Zinc Deficiency Symptoms

Zinc deficiency is characterized by many symptoms like growth retardation, low blood pressure, loss of appetite, weak immunity, and diarrhea. It may also lead to retarded bone growth, loss of taste and smell, pale skin, fatigue, and erectile dysfunction. Lack of zinc is also shown to result in depression, cardiovascular diseases, diabetes mellitus, Alzheimer’s disease, and Wilson’s disease.

Many of these symptoms may also occur due to other underlying health conditions. So, it is important that you consult with an expert and go for a medical examination to confirm whether there is a zinc deficiency or not. [3] [4]

While zinc deficiency is rare, it has a higher chance of occurring in certain groups. They are as follows: [5]

  • Individuals with gastrointestinal disorders
  • Pregnant or lactating women
  • Older infants who are exclusively breastfed
  • Vegetarians and vegans
  • People who have sickle cell disease
  • Those who suffer from alcohol addiction

Food Sources of Zinc

Considering the diet of an average American, the most important food source of zinc is red meat and poultry. Oysters also contain a high amount of zinc per serving. Other foods include beans, nuts, whole grains, dairy products, breakfast cereals, and seafood like lobster and crab.
The reason why most animal-derived foods contain a high level of zinc is that legumes, cereals, and whole grains contain phytates. These compounds bind zinc and inhibit its absorption in your body. If you are on a vegetarian, vegan, or any diet in which you cannot consume animal products, zinc supplements may serve as a helpful option. [6]

Here’s a detailed list of various foods that are high in zinc. If you are looking for information on the benefits, side effects, and dosage of zinc supplements, visit this page.

Health Benefits of Zinc

The most important health benefits of this important mineral are listed below.


Zinc is important for a healthy immune system.

It helps in activating the T-lymphocytes (T cells) in your body. T cells help you in two ways. They control and regulate immune responses and they attack infected cells. [7]

Moreover, a lack of zinc in the body may increase the risk of pneumonia and certain infections in the children and the elderly. [8] [9]

Wound Healing

Zinc helps in keeping the integrity of your skin. It helps in accelerating the wound healing process. It plays an important part in the production of collagen, a connective tissue that is required for skin repair and regrowth. [10]

When oxidative damage increases, your body may find it difficult to heal tissue injuries. This essential mineral is an antioxidant micronutrient that helps in decreasing oxidative stress. It also helps in lowering inflammation and resurfacing of the wound so that your bruise gets healed and covered. [11]

Foods rich in zinc (sliced salmon, meat, prawns, garlic, mushrooms, almonds, cashews, spinach, & legumes) on a wooden table

Zinc helps build your immune system. Photo Credit: Shutterstock


Zinc deficiency may lead to an impaired immune system and therefore, the body is not able to fight infections that cause diarrhea. Many studies associate acute diarrhea with high mortality rates of children in developing countries. [12]

A study published in the American Journal of Clinical Nutrition shows that zinc supplementation may help in reducing the severity of diarrhea in malnourished children. Many other studies also suggest the same. [13] [14] [15] [16]

Common Cold

Researchers from Michigan State University have shown a link between the immune system and zinc levels in the body. [17]

Zinc supplements (specifically in the form of lozenges or syrup) help in decreasing the severity and duration of cold and other mild illnesses. This mineral may help in reducing the number of pro-inflammatory cytokines, which aggravate the body during cold or other infections. Also, its ability to stimulate white blood cell activity makes it ideal for reducing colds and infections. [18]

Dr. Lili He of the University of Missouri, in a study published in Microbiological Research, says that it helps in protecting against infectious disorders and fungal infections, which include pneumonia and conjunctivitis. [19]

Age-related Conditions

Zinc and antioxidants help in healthy aging. [20]

It is an important factor in delaying the progression of age-related macular degeneration (AMD) and vision loss.

A population-based cohort study conducted in the Netherlands shows that high-dose supplementation with beta carotene, vitamins C and E, and zinc may help slow the progression of AMD. [21]

Zinc supplementation may also help elderly people have a robust immune system, which can help in fighting infections. [22] [23]


Inflammation is a potential cause of many health conditions like arthritis and atherosclerosis.

A study published in the American Journal of Clinical Nutrition suggests that zinc may have a protective effect on such diseases. It functions as an antioxidant and an anti-inflammatory agent and helps to keep you healthy. [24]

Sexual Health

Zinc is essential for the repair and functioning of DNA. It is essential for the rapid growth of cells and for the building of major constituents of the cell over the course of a pregnancy. The enormous development and enzymatic activity that takes place during pregnancy make it one of the most important nutrients for infants and mothers. [25]

In females, zinc is vital in embryogenesis and development. In males, zinc assists in spermatogenesis and the development of the sex organs, while in females, it aids in all the reproductive phases, including the parturition and lactation stages. When it comes to sperm, this mineral plays a major role in a number of ways. First of all, it acts as a sort of sedative for the sperm so that they don’t expend unnecessary energy. It also protects the reproductive DNA inside the sperm from breaking down, so a correct transfer of information is guaranteed. Once the sperm enters the female reproductive tract, it quickly dissipates and has a sudden burst of energy, which propels it up in the tube. Finally, it is an essential part of the enzymes that allow sperm to penetrate into the egg. [26] [27]


A deficiency of zinc may lead to neuronal damage as it increases the free radical activity in your brain. [28]

Research shows that consuming foods that are rich in zinc may help lower your risk of such damage. It also plays a key role in helping to prevent alcohol-related brain dysfunction. [29]

Zinc can pair up with vitamin B6 to ensure the proper function of neurotransmitters that communicate within the body. This has been highlighted in a study published in the journal Progress in Brain Research [30]. It is also found in high concentrations in the hippocampus, which controls thought and memory.

Skin Care

Zinc helps in fighting skin conditions like acne, lesions, ulcers, and burns.

It is an important mineral for reducing acne, according to JAMA Dermatology. It regulates and controls the amount of testosterone in the body, which plays a dominant role in causing acne. [31]

In addition to that, zinc is also involved in collagen synthesis. This further aids in normalizing the presence of oil under the skin and improves the maintenance of healthy skin. The open sores that come with acne are practically magnets for bacterial and viral infections and this mineral can stimulate the white blood cell count and reduce the chances of any type of infection. [32]

Other Benefits

  • Protects Prostate Health: Zinc is associated with a healthy prostate. Its deficiency can cause enlargement of the prostate gland. Studies have shown a reduction in tumor growth in the prostate when normal levels of this mineral are present in the system. [33] [34]
  • Improves Sense of Taste & Smell: Zinc has unique benefits, which include the improvement of the senses of taste and smell. Taste buds and olfactory cells are zinc-reliant, and it is necessary for the proper development and growth of those specific cells. [35]
  • Alopecia: Alopecia causes loss of hair in both children and adults. Zinc has been studied to help in accelerating hair follicle recovery. [36]
  • Controls Bone Loss: With age, our bones become weak and fragile. Zinc is a component of hydroxyapatite, which is a salt that makes the bone matrix strong and hard. It plays a role in bone metabolism and may help prevent bone loss and osteoporosis. [37]

Recommended Dosage

The recommended dietary allowance for zinc is 11 mg per day for adult men and 8 mg per day for adult women.

For pregnant and breastfeeding women, the intake is 11mg and 12mg per day respectively.

Also, the tolerable upper limit for zinc is 40mg per day for a healthy individual. This may not apply to people with zinc deficiency or any other condition in which the medical expert has specifically suggested otherwise.

The average daily intake of zinc is easily achievable through a healthy diet. However, if you are suffering through a health condition, do consult with your doctor before starting any zinc supplements. [38]

Zinc Toxicity

Consuming more zinc than the recommended or tolerable limit may have certain acute side effects.

The symptoms of zinc toxicity include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches. Many people have also reported suffering from copper deficiency, weakness in arms and legs, and a weak immune function. [39] [40]

Zinc may also interact with medicines like:

  • antibiotics used for fighting infections,
  • penicillamine, which is used for easing arthritis, and
  • thiazide diuretics that help regulate blood pressure.

Keep in mind these points and include zinc in your diet for a healthy body!

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About the Author

Meenakshi Nagdeve, Co-Founder, Organic Facts is a health and wellness enthusiast and is responsible for managing it. She has completed the Nutrition And Healthy Living Cornell Certificate Program, Cornell University, US. She holds a Post Graduate Diploma in Management from IIM Bangalore and B. Tech in Metallurgical Engineering and Materials Science from IIT Bombay. Prior to this, she worked for a few years in IT and Financial services. An ardent follower of naturopathy, she believes in healing with foods. In her free time, she loves to travel and taste different types of teas.

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