Zinc deficiency – what you need to know
The article below discusses zinc deficiency, symptoms and foods high in zinc.
Zinc is an essential micronutrient, as well as being the most abundant trace element in the body after Iron. Zinc is involved in catalysing enzyme activity, contributes to the structure of proteins, and helps to regulate the expression of our genes. It is also paramount for optimal growth and development. Despite it’s importance to the body, many individuals appear to be supplementing with zinc without having been diagnosed with zinc deficiency. This tends to be the case in affluent individuals/first world countries, where toxicity arises from supplementation where none is required. This is in stark contrast to the suggestion that greater than 25% of the worlds’ population is at risk of zinc deficiency, largely confined to poor and developing countries where access to foods containing zinc is scarce. Long-term supplementation can have adverse side effects too, making it all the more important to accurately select when supplementation is required.
How do I know if I have Zinc deficiency?
Zinc deficiency symptoms include: growth retardation, diarrhoea, alopecia and decreased immunity (among others). However, serum or blood plasma levels are not a reliable measure of overall stores, which makes diagnosing zinc deficiency not a straightforward process. That being said, and along with the symptoms noted above, other instances where zinc deficiency may be an issue include states secondary to disease that impair intestinal absorption and/or increases intestinal loss of zinc, such as inflammatory bowel disease. Other instances where zinc deficiency may be prevalent include: malnutrition, alcoholism, ageing.
Foods high in zinc include: red meat (beef) and poultry, seafood (particularly shellfish), dairy, nuts, some vegetables, pulses and grains. So ensure each week that you consume a wide variety of protein sources, including red & white meat, and seafood where possible. A wide variety of nuts, foods like chick peas and lentils, and dairy products would also contribute to your daily zinc intake. In addition, this presents another instance where zinc deficiency may be common: a vegan diet.
So where might Zinc supplementation be worthy?
Zinc supplementation appears to be beneficial in individuals with Wilson disease (an abnormally high level of copper accumulation in the body, specifically the brain and liver). Zinc also appears effective in treating diarrhoea, particularly in young children, and may be protective against upper respiratory infection, especially in those in developing countries. Lastly, and in combination with antioxidants like vitamin C and E, Zinc may be beneficial in slowing the progression of age related macular degeneration (a condition of the eyes, and read more HERE). A small amount of zinc is lost through sweat, so perhaps individuals who exercise vigorously (regularly) may also be one instance where zinc supplementation is justified.
Summary: Zinc is an incredibly important mineral in the body. At the same time, it appears that most individuals in developed countries – who do not have very rigid/exclusive food preferences – are able to consume sufficient zinc from the diet or adapt to slightly higher or lower levels without severe side effects. Instances where zinc may be worthwhile are: individuals that lack food variety; children with diarrhoea; those with Wilson disease; or elderly individuals seeking to prevent or slow age related macular degeneration. Aside from that, and potentially vegan diets or the elderly with limited appetite and food choice, regular zinc supplementation does not appear to be necessary. ‘Some’ supplementation may be warranted in pregnancy, or professional athletic populations also.
Tip: to consume zinc rich foods eat both lean and fatty meat and fish sources weekly, particularly shellfish if you have access to it. In addition, and although not a ‘fantastic’ food source, most cereals are fortified with minerals, and can therefore be another source of Zinc. Consume nuts, dairy and vegetables, and – where possible – do not over-supplement with other minerals such as Iron or Copper.
NB: if supplementing with iron, consume zinc 2-3 hours apart
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Saper, R.B., and Rash,R. (2009). Zinc: An Essential Micronutrient
Maret, W., and Sandstead, H. H. (2006). Zinc requirements and the risks and benefits of zinc supplementation.