Zinc deficiency: are you missing it without knowing?

Why does your body need zinc?

Zinc is an essential mineral involved in more than 300 enzyme reactions inside your cells. The body needs it to build proteins, copy DNA, divide cells, and mount an immune response. Because zinc supports growth at every level, children, pregnant women and adolescents need it most. Dr Ananda Prasad first described human zinc deficiency in the 1960s when he observed stunted growth in young men in Iran and Iraq whose diets consisted mainly of bread and fava beans, as he described in a landmark review in Advances in Nutrition in 2013.

Zinc sits at the centre of immune defence. A comprehensive review published in Nutrients in 2020 found that even a mild shortfall in zinc reduces the activity of immune cells and prolongs infection. In practical terms, you may notice that you catch colds more often than others, or that small cuts and grazes seem to take longer than usual to close.

A function less widely known is zinc's role in smell and taste. When those two senses fade without an obvious cause, zinc deficiency is one of the first things a clinician considers. Zinc also helps regulate blood sugar and speeds skin repair, which is why it matters particularly to people with diabetes.

Who is most at risk in the Middle East and North Africa?

A study published in Biological Trace Element Research in 2003 measured zinc levels across an Arab population in Kuwait and found meaningful deficiency rates even in a relatively prosperous urban setting. The core reason is that the regional diet relies heavily on bread, rice, lentils and chickpeas. These foods contain phytate, a naturally occurring compound that binds zinc in the gut and prevents absorption. The more phytate in a meal, the less zinc you actually absorb regardless of what the food label says.

Children under five are most vulnerable because their bodies are growing fast and their relative zinc requirement per kilogram of body weight is highest. Pregnant and breastfeeding women need more zinc than usual. People with chronic gut disease such as Crohn's disease, liver cirrhosis, or persistent diarrhoea lose zinc faster and absorb it less efficiently. Older adults also absorb zinc less well as enzyme activity declines with age.

Displaced or conflict-affected populations face a particular risk. Humanitarian food rations focus on calories and tend to be grain-based, with little meat or dairy. A study on nutritional deficiencies in Gaza published in Food and Nutrition Bulletin in 2020 identified zinc as one of the most prominent shortfalls, with direct consequences for child growth and infection vulnerability across the region.

What are the signs of zinc deficiency?

The difficulty with zinc deficiency is that its signs overlap with many other conditions, which is why a dietary assessment and a blood test are more reliable than symptoms alone. The most recognisable sign is that wounds, even small ones, take noticeably longer than usual to heal. Hair thinning or shedding without a clear cause is another common presentation.

Reduced ability to smell or taste food is a hallmark of more significant zinc shortfall. You may also find that you catch infections more readily than you used to. In children, the deficiency can appear as slower-than-expected height and weight gain, reduced appetite, and delayed sexual maturation. These are the signs that prompted Prasad's original observations in the 1960s.

Severe deficiency can cause a distinctive skin rash that appears around the mouth, eyes and genital area, a condition called acrodermatitis enteropathica when it results from a rare genetic failure to absorb zinc. This severe form is uncommon but illustrates just how dependent both the gut lining and the skin are on adequate zinc at a cellular level.

The best zinc food sources in a regional diet

Oysters and other shellfish are the richest dietary sources of zinc by far. They are not universally available across the Arab world, but they are eaten in Gulf coastal areas and along the Levant coast. Red meat including beef and lamb provides very good zinc that the body absorbs efficiently. A small 85 gram serving of cooked beef delivers around 5 to 6 milligrams, covering roughly half the daily recommended amount for a man.

Liver, heart and kidney, which are used regularly in Arab cooking, are also excellent sources. Chicken provides less zinc than red meat but is still a meaningful contributor when eaten regularly. Among plant sources, pumpkin seeds, cashews, lentils and chickpeas contain zinc, but research published in The Journal of Nutrition in 2000 showed that the phytate in these foods reduces the amount the body can actually absorb to between 15 and 35 percent of the total present.

Practical steps to improve zinc uptake from plant foods include soaking legumes overnight and discarding the water, allowing bread dough to ferment before baking, and eating a small portion of meat or fish alongside legume dishes. Shifting strong black tea drinking to an hour after meals rather than during them also helps, because tannins in tea reduce absorption of several minerals.

Why zinc matters so much for children with diarrhoea

The World Health Organization recommends giving zinc supplements to all children under five with acute diarrhoea for ten to fourteen days. Diarrhoea rapidly depletes zinc stores in the body, and zinc deficiency in turn makes the gut lining more permeable and less able to defend against infection, which extends the illness and raises the chance of another episode within weeks.

A review published in Nutrients in 2023 confirmed that adding zinc to standard oral rehydration therapy in children reduces the duration and severity of acute diarrhoea and lowers mortality in low-income settings. This makes zinc one of the most cost-effective child health interventions available, which is especially relevant in Yemen, Sudan, Syria and parts of Egypt where diarrhoeal disease remains a leading cause of child death.

If your child has repeated episodes of diarrhoea, seems to grow more slowly than expected, or has a poor appetite alongside frequent infections, it is worth discussing zinc testing with a doctor. Blood zinc levels are an imperfect measure of total body zinc, so the doctor will consider the result alongside dietary history and symptoms rather than acting on the number alone.

What does a zinc blood test show and what is normal?

Zinc is measured in blood plasma or serum, referred to as serum zinc or plasma zinc on a lab report. Normal levels in adults generally fall between 70 and 120 micrograms per decilitre (µg/dL), though reference ranges vary between laboratories. Always compare your result against the range printed on your own laboratory report rather than a number you read elsewhere.

The test is sensitive to several variables. Taking the sample right after eating, having an active infection, or haemolysis of the blood sample can all lower the measured level falsely. For this reason, clinicians interpret zinc levels alongside symptoms, dietary assessment and clinical judgement rather than treating the number in isolation.

In many cases a doctor will offer a therapeutic trial of zinc supplementation when symptoms are convincing and the diet is clearly deficient, even if the blood level sits in the lower part of the normal range. Rapid improvement in symptoms within two to four weeks confirms the diagnosis in practice.

When is a zinc supplement useful, and when does it cause harm?

A zinc supplement is genuinely useful when deficiency is confirmed or clinically likely, when caring for a child with acute diarrhoea in a resource-limited setting, or when pregnancy coincides with a diet low in animal protein. The recommended daily intake is 8 milligrams for adult women and 11 milligrams for adult men, rising slightly during pregnancy and breastfeeding. Common supplement forms include zinc gluconate, zinc acetate and zinc picolinate; differences in absorption between them at standard doses are modest.

Taking high doses over a long period causes problems of its own. Zinc competes with copper for intestinal absorption. Sustained intake above 40 milligrams per day in adults depletes copper and can lead to anaemia and nerve problems that may take months to become apparent. High doses also cause nausea, vomiting and stomach cramps in the short term. Do not take zinc supplements at high doses without medical guidance.

If you are taking tetracycline or quinolone antibiotics such as ciprofloxacin, or penicillamine for rheumatoid arthritis or liver disease, be aware that zinc binds to these drugs in the gut and reduces how much of them you absorb. Separate the zinc supplement and these medicines by at least two hours when a doctor has prescribed both.

How to improve your zinc intake through everyday food choices

The safest and most sustainable way to raise zinc status is through food rather than supplements. Including red meat or poultry three to four times a week is usually enough to meet daily needs for most adults. You do not need large portions. An 85 gram portion of cooked beef delivers roughly 5 to 6 milligrams of highly available zinc, which is more than half of a man's daily requirement.

For those who eat little or no meat, preparation methods matter significantly. Soaking legumes overnight and discarding the soaking water reduces phytate content. Allowing bread dough to ferment with yeast degrades phytate. Roasting seeds and nuts has a similar effect. Eating a small amount of animal protein alongside a legume dish also improves mineral absorption from the plant food in the same meal.

If you take an iron supplement at a high dose, be aware that iron and zinc compete for absorption, so taking large iron supplements can reduce zinc uptake. If you are taking more than one mineral supplement, ask your doctor or pharmacist about the best timing to separate them through the day for maximum benefit.

Sources

• Prasad AS: Discovery of human zinc deficiency: its impact on human health and disease, Advances in nutrition (Bethesda, Md.), 2013
• Abiaka C, Olusi S, Al-Awadhi A et al: Reference ranges of copper and zinc and the prevalence of their deficiencies in an Arab population aged 15-80 years, Biological trace element research, 2003
• Lonnerdal B: Dietary factors influencing zinc absorption, The Journal of nutrition, 2000
• Chao HC: Zinc Deficiency and Therapeutic Value of Zinc Supplementation in Pediatric Gastrointestinal Diseases, Nutrients, 2023
• Saper RB, Rash R: Zinc: an essential micronutrient, American family physician, 2009
• Gombart AF, Pierre A, Maggini S et al: A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection, Nutrients, 2020
• Nasreddine LM, Kassis AN, Ayoub JJ et al: Nutritional status and dietary intakes of children amid the nutrition transition: the case of the Eastern Mediterranean Region, Nutrition research (New York, N.Y.), 2018