Have you visited your neighborhood grocery store recently? If so, you’ve probably seen shelves at the front of the store dedicated to vitamins and minerals that support your immune system.
This is because viruses causing the flu, colds, and other respiratory illnesses are commonly spread throughout the colder months.
One common mineral you’ve probably come across on these shelves is zinc.
What is zinc?
How does zinc work in your body?
What are the different forms of zinc?
What are the signs, symptoms, and causes of zinc deficiency?
Let’s explore these questions and more in this blog post.
What is zinc?
When you hear the word “zinc,” what do you think of?
Some of you may picture sunscreen, whitening toothpaste, or dandruff-treatment shampoos. Or maybe you’re thinking of zinc metal or the Earth’s crust.
While these substances contain zinc, let’s focus specifically on zinc for your health. Zinc is an essential mineral that your body needs for cellular metabolism – biochemical reactions that take place in your cells to help your body function properly and sustain life. Similar to vitamin C, it’s important for your immune system, wound healing, and eye health. We’ll explore these benefits and more in the next section.
What does zinc do in the body?
Your body needs zinc to function properly. Here are some of the organs, hormones, and systems that use zinc.
1. Immune System Support
Your body needs zinc to activate T cells, a type of white blood cell that helps your body fight diseases (and possibly even cancer cells). Let’s dig into this process in more detail.
- If you’re deficient in zinc, your thymus gland will shrink.
- You need a proper functioning thymus gland to create T cells.
- Since there’s a reduction in T cells, this causes your lymphocyte count to go down. Your lymphocytes are the soldiers in your body that help to fight disease and infections.
- Your immune system won’t respond correctly, and you’ll have a decrease in white blood cell response.
- This may lead to you being susceptible to viruses and infections
On the other hand, a study found that a zinc supplement was able to reduce respiratory morbidity and improve the health of pre-school-aged children. This may be because zinc can function as an anti-oxidant and has anti-inflammatory properties also.
2. Wound Healing
Ever experienced a paper cut? They’re pretty painful. Your body needs to go through a number of steps in order for your cut to heal. These steps include coagulation, inflammation, angiogenesis, new tissue formation, and extracellular matrix remodeling.
Collagen is the main structural protein in the extracellular matrix of your connective tissues, including your skin. So your body needs collagen in the wound healing process.
Where does zinc tie into collagen and wound healing?
Well, zinc activates proteins that are essential for collagen synthesis. Since collagen is the backbone of our skin, zinc plays a big role in promoting wound healing.
3. Thyroid
Your thyroid hormones are affected by your zinc metabolism, your body’s ability to absorb and excrete zinc. So if you’re deficient in zinc, your thyroid hormones will be affected. The hormones that are affected include T3, T4, and thyroid-stimulating hormone (TSH).
This problem may be due to your thyroid hormones’ need for zinc to bind to receptors. If thyroid hormones can’t bind to receptors, the hormone receptors can’t send a signal to your brain. Your brain won’t be able to determine how much thyroid hormone is in your bloodstream and therefore won’t be able to upregulate or downregulate it.
4. Sex Hormones
Zinc is important for sex hormones in both males and females. It’s important when spermatozoa form and mature, for ovulation, and for fertilization. A study done in chronic renal failure patients found that zinc supplement therapy increased the serum levels of testosterone and luteinizing hormone.
As you age, your testosterone levels will lower while your dihydrotestosterone levels may increase. This can lead to hair loss, and in men, prostate problems. Zinc can help to naturally increase testosterone to prevent or reduce these symptoms from occurring. For luteinizing hormone, it’s released from your pituitary gland to make free testosterone and thyroid hormones.
While more of a mechanistic issue, zinc plays a huge part in gene expression and function. Your thyroid hormones, sex hormones, and vitamins carry out their gene expression by binding to nuclear receptors in cells. These nuclear receptors will bind to your DNA by using zinc finger motifs.
What are zinc finger motifs and how does this impact your sex hormones?
In your nuclear receptors, a zinc ion is needed to coordinate the primary structure of proteins into a finger shape. Similar to your hands interlocking when you clasp your fingers together, a zinc finger motif is when zinc binds to DNA and hormone receptors. If you’re deficient in zinc, your body can’t create the zinc finger motif which can lead to issues with hormone function, including your thyroid and sex hormones.
5. Blood Sugar Regulation
Diabetes is one of the leading causes of death worldwide. Several studies have shown the benefits of zinc in type-1 and type-2 diabetes. Oxidative stress appears high in diabetic patients, so zinc’s antioxidant properties may play a role in reducing this.
Zinc is also important in glucose and lipid metabolism. Zinc promotes glucose metabolism and storage while reducing glucose absorption and synthesis, fasting plasma glucose, and serum insulin.
It appears that zinc acts like insulin by binding to insulin receptors, activating signaling pathways, and clearing glucose from the blood. Since zinc is tied closely to insulin function, a zinc deficiency may result in insulin resistance.
6. Hair Growth
A study found that patients who were dealing with hair loss had lower concentrations of zinc in their bodies. The researchers hypothesized that zinc metabolism disturbances may have played a key role in hair loss.
Other studies have examined patients with alopecia, an autoimmune disorder that causes hair loss. Patients with alopecia were able to experience hair regrowth after taking a zinc supplement. In one study, patients supplemented with oral zinc gluconate tablets (50 mg/tablet per day) for twelve weeks. These patients were able to increase their serum zinc levels significantly. The sample size was small 15 patients), so more studies may need to be conducted.
An in vivo study with mice found that the mice given zinc for an extended period of time actually experienced a retard with hair re-growth. More studies need to be completed to see if excess zinc supplementation could be hurting human hair growth. This is also an important reason why it is crucial to check blood levels–levels that are too high can also affect how we absorb and metabolize other minerals. Like most nutrients, we are wanting to achieve an optimal level (not too high, not too low).
Many of the studies mentioned above were performed on individuals or animals with zinc deficiency. It may be important to replicate the experiments in individuals who have sufficient amounts of zinc to see if similar results are obtained. However, this doesn’t diminish the findings that zinc is vital for many bodily systems.
What are the different forms of zinc?
Just as there are several forms of magnesium you can supplement with, there are also different forms of zinc that are available. They include:
- Zinc sulfate
- Zinc oxide
- Zinc citrate
- Zinc acetate
- Zinc glycinate
- Zinc picolinate
- Zinc monomethionine
The least expensive forms of zinc are zinc oxide and zinc sulfate, but it’s hard to absorb and may cause stomach irritation. The amount of elemental zinc in each supplement will depend on the form of zinc. My favorite form of zinc is zinc glycinate, as it is easily absorbed and friendly to the GI tract. I do usually advise zinc to be taken with food, which also helps patients tolerate it quite well.
In order to reduce the risk of viral infections and symptoms, zinc lozenges may be taken. The lozenge should be dissolved in the mouth and not taken as a pill as it’s a more effective way to get zinc to your mucous membranes, the main mechanism you’ll get a viral infection from.
Be sure to speak with your doctor before taking zinc. Some medications may interfere with zinc or cause side effects. Zinc should also not be taken for an extended period of time; the dosage and period that you’ll take the supplement are determined by your doctor. Lastly, there’s a strong relationship between zinc and copper. If you have too much zinc in your body, you may become deficient in copper and vice versa. This is why zinc may be used to treat patients with Wilson’s disease, a disease that causes the build-up of copper.
What are the signs and symptoms of zinc deficiency?
The symptoms that you’ll experience if you’re deficient in zinc will vary. Early symptoms of zinc deficiency include:
- Rashes
- Fatigue
- Hair loss
- Irritability
- Loss of appetite
- Slow wound healing
- Impaired immune system
- Hormone imbalances
- Blood sugar dysregulation
- Impaired sense of taste and smell
- Slow growth and development in infants and children
Some severe zinc deficiency symptoms include:
- Night blindness
- Clouding of the cornea
- Behavioral disturbances
- Delayed sexual maturation
- Frequent chronic infections
Your doctor can conduct blood and/or urine tests to determine if you’re deficient in zinc.
What are the causes of zinc deficiency?
About 17% of the global population (over 1.3 billion people) are at risk for inadequate zinc intake. One of the most common causes of zinc deficiency is malnutrition. Your body can’t store excess zinc, so you need to ensure that you are intaking proper amounts of zinc daily. Along with a diet that’s low in zinc, inadequate zinc intake could be due to the loss of zinc during food processing.
The second common cause of zinc deficiency is excess losses of zinc through diarrhea, digestive fluids, or urination. Zinc deficiency is also linked to alcoholism, gastrointestinal tract disorders, and renal disease.
A third cause of zinc deficiency is malabsorption. This is tied with the second cause of zinc deficiency. When your body isn’t able to absorb the zinc that it’s acquiring from foods, you may experience zinc deficiency. Some inhibitors include medications such as penicillamine and diuretics and foods like nuts that contain phytates. While nuts contain a high amount of zinc and are included as foods rich in zinc in the next section, you may need to pre-treat the nuts through milling, fermentation, or soaking to increase the absorption.
The most common causes of zinc deficiency are malnutrition, excess loss of zinc through bodily fluids, and malabsorption. Other causes that may make you deficient in zinc include stress, high intake of processed foods, genetic disorders, and yeast overgrowth. The most severe cause of zinc deficiency is in children affected with the autosomal-recessive trait, acrodermatitis enteropathica. This is a disorder of zinc metabolism; the child isn’t able to use zinc from common foods for cellular processes.
While you may be deficient in zinc, a common way to reverse this is through eating foods rich in zinc. Let’s explore this in the next section.
What foods are rich in zinc?
Eating foods that contain zinc is the best way to treat a zinc deficiency. Below is a list of foods that contain a high amount of zinc.
1. Oysters
Oysters are reported to have the largest amount of zinc compared to any food. You can receive up to 673% of the recommended daily value of zinc in just three ounces of oysters that are cooked.
While oysters have their health benefits when it comes to zinc, too much can also be harmful to your health. It’s also important to ensure that the oysters are cooked as consuming raw forms of seafood may contain bacteria and heavy metals. Pregnant and breastfeeding women, children, and immunocompromised individuals should not consume raw seafood.
2. Grass-fed beef
While beef contains a high amount of iron, it also contains an abundant amount of zinc. One lean grass-fed steak (about 214 g) contains 7.7mg of zinc.
In addition to its zinc benefits, grass-fed beef is a ketogenic friendly food that’s clean and protein-rich. If you’re looking for a recipe to try, you can check out my rosemary garlic grass-fed beef burgers.
3. Pumpkin seeds
Pumpkin seeds are one of the most concentrated sources of zinc. If you’re a vegetarian, they can ensure you receive the recommended quantity of zinc. The National Institute of Health reported that the recommended dietary allowance for zinc in adult male adults is 11 mg and in adult females is 8 mg.
There is about 8 mg of zinc in 100 g of pumpkin seeds, which demonstrates how much zinc you can actually consume from the seeds!
4. Chia seeds
In addition to pumpkin seeds, chia seeds are a great source of zinc. One hundred grams of chia seeds contain 4.58 mg of zinc. They also contain a high amount of dietary fiber, omega-3 fatty acids, and magnesium. You can try my kale avocado smoothie bowl and add chia seeds for the extra nutrients.
Other seeds such as flax seeds, poppy seeds, sesame seeds, and sunflower seeds contain a high amount of zinc.
5. Nuts
Like seeds, nuts contain a high amount of zinc. A study found that cashew nuts contained a high concentration of zinc. Almonds, brazil nuts, and pistachios contain a high amount of zinc too. Nuts are a great addition to granola, chocolate truffle fudge, and a chocolate berry smoothie.
6. Green peas
While green peas probably weren’t your favorite vegetable growing up, they contain a large percentage of your recommended daily allowance (RDA) of zinc. A study found that United States-grown field peas contained between 36-78% RDA of zinc. Green peas also contain a large percentage of iron and magnesium.
7. Avocado
In the fruit category, avocados contain a large percentage of zinc. One raw avocado contains about 12% of the daily value of zinc your body needs. It’s also a great source of magnesium and potassium.
While the foods listed above are a great source of zinc, this is not a comprehensive list. There are other types of meats, vegetables, nuts, seeds, and fruits that can provide your daily requirement of zinc. As stated above, since your body can’t store excess zinc, it’s important to continuously intake it through a variety of foods.
Do you have questions about zinc? Here’s how we can help.
Zinc is an important mineral that your body needs for a variety of processes: from immune function to mitochondrial health and much more. If you think you may be experiencing symptoms of zinc deficiency or would like to speak with a doctor, you can schedule an appointment here.
Here’s to getting down to the root cause of your health conditions together!
Dr. Emily Parke