Micronutrient Monday: Zinc

Although we may often forget about it, zinc is another important micronutrient that our bodies require. Zinc is a mineral that is naturally found in many foods and required to make proteins.

Our bodies require zinc for many important functions. Zinc is an important part of proteins and enzymes that control gene expression. Without it, our bodies would not be able to produce the proteins that we require. It can also control the release of hormones and is needed to send nerve signals and start other cell signalling pathways.

Health Canada recommends healthy individuals over the age of 14 consume between 8 to 11 milligrams of zinc each day. The recommended intake for zinc can vary based on age, sex, lactation and pregnancy. Check out Health Canada’s website for more information and a complete list of zinc requirements.

Am I At Risk of Deficiency?

Zinc deficiency tends to be uncommon as it can abundantly be found in many foods. However, there are some populations that have an increased risk of developing a deficiency. Some populations that are at an increased risk of zinc deficiency include,

• • Pregnant individuals
  • Vegetarians or vegans 
  • Individuals with digestive disorders (such as inflammatory bowel disease or gastrointestinal surgery)
  • Individuals with chronic liver or kidney disease 
  • Individuals with prolonged periods of diarrhea 

Some signs of zinc deficiency include,

• • Loss of taste or smell 
  • Poor appetite 
  • Decreased ability to fight infections 
  • Slow wound healing 
  • Depression
  • Hair loss 

Can I Have Too Much Zinc? 

Although there is enough zinc in our diet to meet our bodies’ needs, it rarely causes toxicity. Zinc toxicity mainly occurs from excessive use of zinc supplements. Some signs of zinc toxicity include,

• • Headaches 
  • Nausea and vomiting 
  • Diarrhea 
  • Decreased appetite 
  • Stomach pain or cramping

If you are not taking zinc supplements, your chances of developing zinc toxicity are extremely low.

There are many zinc-containing foods that can be included in our diets. Some of the top zinc-rich foods include,

• • Oysters 
  • Beef 
  • Alaskan king crab 
  • Pork chops 
  • Baked beans 
  • Breakfast cereal (some of cereals are forted with zinc) 
  • Pumpkin seeds 
  • Yogurt 
  • Cashews 

If you are not meeting the recommended zinc intake, you can include more of these zinc-rich foods in your diet or explore supplementation options with your dietitian or doctor.

Supplements

There are many types of zinc supplements available at most pharmacies. Zinc supplements are available in many forms including, pills, lozenges and nasal sprays and gels. Lozenges are known to have some unpleasant side effects such as a metallic flavour and nausea and vomiting.

Consuming high doses of zinc can also cause nausea and vomiting, as well as a decrease in the absorption of iron and copper from our digestive tract. It is important to chat with your dietitian or doctor before taking zinc supplements due to the severe negative side effects.

What About Zinc Lozenges for Colds and Flu?

Many people believe zinc can reduce the duration and cure colds. However, that’s not quite the case. Research on zinc has shown mixed results. Although zinc lozenges will not stop you from getting a cold, they can help reduce the severity of the symptoms.

Other Products

It’s also important to keep in mind that zinc is found in many other products such as homeopathic medications and over-the-counter flu medications, and denture adhesive creams. Using these products as directed does not lead to zinc toxicity, however excessive use of these products may result in zinc toxicity.

Interactions with Medications

Zinc found in the food we consume does not tend to interact with medications, however, zinc supplements may interact with some medications, decreasing their effectiveness or producing adverse effects. Some medications that may interact with zinc supplements including,

• • Antibiotics 
    • Tetracycline and quinolone antibiotics can interact with zinc in our digestive tract, leading to decreased absorption of both the antibiotic and zinc.
  • Penicillamine
    • Penicillamine is a drug used in the management of rheumatoid arthritis. However zinc supplements can interact with this drug and change how effective it is. 

  • Diuretics

    • Thiazide diuretics can lead to increased excretion of zinc in the urine. Prolonged use of thiazide diuretics can lead to a decline in the amount of zinc stored in our bodies’ tissues.  

For more on the role of vitamin and minerals in promoting health and supporting our bodies, check out the Micronutrient Monday series.