Zinc is an important mineral that plays a vital role in keeping you healthy by supporting your immune system. Although numerous foods contain zinc, a deficiency can cause zinc nausea, among other symptoms. Nausea can also be a zinc supplement side effect from taking too much of a zinc vitamin-mineral supplement.
You might find zinc useful to prevent or treat many conditions, including the common cold, pregnancy-related complications, chronic diarrhea, respiratory infections, anemia and male fertility problems, but use caution with the dosage because zinc can be toxic.
The Importance of Zinc
Although your body doesn't need a lot of it, zinc is an essential trace mineral found throughout the cells in your body. Many aspects of cellular metabolism depend on zinc. Over 300 enzymes need zinc for the ability to carry out many bodily functions including:
- Cell division
- Healing wounds
- Breaking down carbohydrates
- Maintaining your immune system
- Synthesis of hormones
- Supporting your senses, such as smell and taste
- Enhancing the action of insulin
How Much Zinc?
The current recommended daily allowance for zinc set by the Food and Nutrition Board has been designated according to age and sex. These values are the estimated total requirements from foods high in zinc, including fortified foods, water and supplements, as follows:
- Children: 4 to 8 years of age — 5 milligrams; 9 to 13 years of age — 8 milligrams
- Males: 14 years and older — 11 milligrams
- Women: 14 to 18 years of age — 9 milligrams; 19 years and older — 8 milligrams
- Pregnant and lactating women: 11 to 13 milligrams
Causes of Zinc Deficiency
If you are having a hard time getting an adequate supply of zinc, there may be a medical reason that could be preventing your body from absorbing the mineral. Several conditions may put you at risk for a zinc deficiency, including:
- Being a vegan or vegetarian
- Having a digestive disorder, such as Crohn's, IBS, chronic diarrhea or malabsorption syndrome
- Having a chronic kidney or liver disease
- Having diabetes
- Increased zinc loss from burns or prolonged diarrhea
Zinc Nausea From Deficiency
It is estimated that 2 billion people worldwide are deficient in zinc. Children are especially susceptible to zinc deficiency, which contribute to impaired physical and neuropsychological development and risk of infection, especially in young children who live in developing countries.
One of the symptoms of low levels of zinc is nausea. Other symptoms associated with zinc deficiency include:
- Loss of appetite
- Growth retardation and development
- Weakened immune system
- Hair loss
- Slow wound healing
- Poor sense of taste and smell
- Delayed sexual maturation
- Rough dry skin and rashes
- Chronic and severe diarrhea
Food Sources of Zinc
Zinc is not stored in your body, so you must get a daily supply from food to maintain adequate levels. Many foods contain zinc, but the best source is oysters, with 74 milligrams per 3-ounce serving. That equates to 494 percent of your recommended daily allowance. Other good sources of zinc include:
- Red meat, such as beef
- Fish and seafood, especially flounder, crab and lobster
- Legumes, including baked beans, kidney beans and chickpeas
- Dairy products, such as yogurt, cheese, milk
- Nuts, like almonds and cashews
- Whole grains
Many foods are fortified with zinc, including cereals and health bars. Although grains and plant foods are still good sources of zinc, some contain phytates, which bind to zinc and inhibit its absorption. Therefore, the bioavailability of zinc from these foods is lower than from animal-based foods.
Using Zinc Supplements
If you include enough zinc-rich foods in your diet, you probably won't need to worry about taking a zinc supplement. However, if you decide additional zinc could be of benefit to you, several forms are available. Each type may have differences in absorption, tolerability and bioavailability.
Taken as a supplement, zinc is used to treat or prevent a variety of conditions. Zinc plays a role in men's health because the prostate accumulates the highest level of zinc of any soft tissue in the body. The benefits of zinc for sexual health is demonstrated by its potential to boost or modulate testosterone levels in men, as indicated in a June 2014 study in the Journal of Plant Biochemistry & Physiology.
Evidence also suggests that zinc has a protective effect against the risk for developing prostate cancer, according to the April 2013 study in Nature Review Urology.
Zinc is well known for its use in cold remedies but it is also used to reduce the incidence of respiratory infections, such as pneumonia, and diseases, such as malaria. Zinc therapy is used to help reduce acute diarrhea in children and prevent birth complications for pregnant women.
Zinc Nausea From Supplements
You should only take zinc supplements under the advice of a health care professional and not in doses exceeding the recommended daily upper limit of 40 milligrams as determined by the National Institutes of Health. When taken orally, zinc supplement side effects can include nausea and other symptoms such as:
- Metallic taste
- Stinging, itching or tingling skin
Be aware that long-term use above the recommended upper level increases your risk of serious adverse health effects from zinc toxicity.
Causes of Zinc Toxicity
Although it's unlikely you could get too much zinc from food alone, a zinc overdose can result from excessive intake of a combination of food and various other sources, such as zinc vitamin-mineral supplements, prescribed medications, over-the-counter cold medicines and homeopathic remedies that contain zinc. In addition, accidental ingestion of household and skin products that contain zinc oxide could also create a toxic situation. Zinc oxide is used in many products such as:
- Zinc oxide ointment
- Diaper rash medicines
- Hemorrhoid medicines
- Skin lotions
- Calamine lotion
- Sunscreen lotion
Linus Pauling Institute reported zinc toxicity outbreaks resulting from eating food or drinking beverages contaminated with zinc released from galvanized containers.
Zinc Nausea From Toxicity
A too high intake of zinc may result in side effects with symptoms ranging from mild to severe. Intake of 50 to 150 milligrams per day of supplemental zinc may cause minor intestinal distress occurring within three to 10 hours after ingestion. Single doses of 225 to 450 milligrams of zinc usually cause nausea and induce vomiting. Other symptoms include:
- Severe dehydration
- Abdominal cramps
Zinc oxide poisoning can result from accidentally ingesting certain creams and ointments used for minor skin irritations or burns. Inhaling zinc oxide fumes can also cause toxicity resulting in symptoms of zinc nausea, vomiting, stomach pain and diarrhea.
Read more: Maximum Zinc Doses
Loss of Sense of Smell
If you are suffering from a cold and use over-the-counter remedies, be aware that many preparations contain zinc. Zinc lozenges may help relieve your sore throat, but they can have side effects including nausea and leave a bad taste in your mouth. Nasal gels and nasal sprays can also contain zinc and have been reported to cause a loss of sense of smell (anosmia) that may be long-lasting or even permanent, according to the National Institutes of Health.
Copper Deficiency & Iron Absorption
Taking 50 milligrams per day or more of zinc supplements long- term can interfere with copper bioavailability.
Zinc binds with copper and competes with copper for similar binding sites in your body. As a result, excessive zinc decreases uptake of copper into the blood, according to a March 2013 study published by Advances in Nutrition. Conclusions of the study confirmed that too much zinc can produce a chronic negative copper balance. Zinc-induced copper deficiency can lead to several disorders involving iron absorption, such as iron deficiency anemia.
Copper deficiency can also affect your nervous system, causing weakness and numbness in the legs and arms, according to Mayo Clinic.
A copper deficiency can also be a concern for denture wearers. Dental adhesives creams often contain zinc with levels ranging from 17 to 34 milligrams per gram. Excessive use of these products can result in zinc toxicity, which may cause irreversible neurological damage, according to a BMJ Case Reports article published in August 2017.
- NIH: MedlinePlus: "Zinc"
- Oregon State University: Linus Pauling Institute: "Zinc"
- NIH: MedlinePlus: "Zinc in Diet"
- National Institutes of Health: "Zinc"
- Nature Reviews: Urology: "Zinc and Zinc Transporters in Prostate Carcinogenesis"
- Journal of Plant Biochemistry & Physiology: "Increasing Circulating Testosterone Impact of Herbal Dietary Supplements"
- AllinaHealth: "Zinc Oxide Overdose"
- Drugs.com: "Zinc Side Effects"
- Mayo Clinic: "Zinc"
- Advances in Nutrition: "Discovery of Human Zinc Deficiency: Its Impact on Human Health and Disease"
- University of Virginia: "Considerations in the Copper Deficient Patient"
- BMJ Case Reports: "Zinc Containing Dental Fixative Causing Copper Deficiency Myelopathy"