Zinc is an essential trace mineral which plays a vital role in numerous cellular processes. It is the second most abundant micronutrient in the body after iron, with the adult body holding about 2.6 grams, primarily in the bones, muscles, skin and liver.¹

Maintaining healthy levels of zinc is crucial for a number of biological functions including hormonal health, immune system function, neurotransmitter synthesis and wound healing, among other processes.

Adult females are recommended to consume 8mg zinc per day, and adult men are recommended to consume 14mg per day.² As there is no designated storage organ for zinc, it must be continually replenished through dietary intake.¹ For most healthy individuals, adequate zinc levels can be maintained via a healthy and varied diet.

According to the Australian Food Composition Database, the highest food sources of zinc are as follows: ³

Animal food sources: oysters, lamb, mutton, beef, goat, veal, kangaroo, parmesan cheese, crab.

Plant food sources: yeast, sundried tomato, poppy seed, popped rice, wheatgerm, cocoa powder, cardamom.

Plant foods generally have lower levels of zinc (per 100g) compared to animal foods, and phytates in plant foods may also impair zinc absorption.  

Zinc deficiency

While serious zinc deficiency is less common in developed countries, some populations may still be at risk of deficiency such as pregnant women, vegans and vegetarians and those with gastrointestinal conditions such as Crohn’s disease.⁴ Symptoms of zinc deficiency include hair loss, skin changes, poor wound healing, impaired immune function, diarrhoea and loss of smell and taste.⁴

Zinc deficiency may be diagnosed via blood test, however this is not only unreliable for detecting mild deficiency, but may not accurately reflect zinc status as serum zinc levels may change during inflammation, stress or after dietary intake.^1,4 Careful assessment of symptoms, dietary intake and interfering factors may help clinicians establish zinc status. According to the Australian national health advice service, HealthDirect, an effective method of diagnosing zinc deficiency is seeing if symptoms improve with zinc supplementation.⁴

Zinc supplementation

Zinc supplementation is a low risk and cost-effective treatment to correct zinc deficiency in most cases. Zinc supplementation may also be of benefit in certain cases where demand is increased such as in preconception, after illness, and in certain health conditions such as premenstrual syndrome. There are some important factors to consider however when using zinc supplements:

• Certain forms of zinc are better absorbed than others. For example, zinc bisglycinate has been shown to have higher bioavailability than other forms such as zinc sulfate.⁵ Other forms of zinc may have specific uses, such as zinc carnosine for supporting mucus membrane integrity.
• Long term and/ or high dose zinc supplementation may displace copper due to their competitive absorption pathways. Consider the need for zinc supplementation long term, and potentially increase copper intake if required.
• Dosing zinc correctly may determine the success of the treatment. Lower doses of zinc may require longer treatment periods, and doses which are too high may be associated with some negative side effects such as nausea.

To understand the complexities of zinc supplementation, always work with a healthcare practitioner trained in nutrition and supplement use before supplementing with zinc.

Contact your natural healthcare practitioner or find your local BioMedica practitioner here.

References

1. Maares, M., & Haase, H. (2020). A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models. Nutrients, 12(3), 762. https://doi.org/10.3390/nu12030762
2. National Health and Medical Research Council. (n.d.). Zinc. Eat For Health. https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/zinc
3. Food Standards Australia New Zealand. (n.d.). Foods by nutrient: Zinc. Australian Food Composition Database. https://afcd.foodstandards.gov.au/foodsbynutrientsearch.aspx?nutrientID=ZN
4. Healthdirect Australia. (n.d.). Zinc deficiency. https://www.healthdirect.gov.au/zinc-deficiency#:~:text=Zinc%20deficiency%20can%20result%20in,time%20to%20heal%20and%20diarrhoea
5. Ośko, J., Pierlejewska, W., & Grembecka, M. (2023). Comparison of the Potential Relative Bioaccessibility of Zinc Supplements-In Vitro Studies. Nutrients, 15(12), 2813. https://doi.org/10.3390/nu15122813