Zinc has been called a 'metal of life' because of its status as the single most important micronutrient to our health. It is vital for proper growth and development from sperm and egg fertilisation, fetal development, and early child development. It helps to regulate hormones, maintain a healthy metabolism, and strengthen our immunity. Zinc even plays a role in ensuring we have a quality sense of taste and smell. However, an estimated 17% of people worldwide have inadequate zinc in their diet each day. This can lead to zinc deficiency, which increases the risk of infection, disease, and abnormal development.
There are several reasons why you may develop a zinc deficiency. People who are particularly vulnerable to zinc deficiency include pregnant women and those with inflammatory bowel disease. Any chronic infection or symptom increases the daily need for zinc. For example, inflammatory bowel disease often involves ongoing diarrhea and vomiting. This results in people with this chronic disease having a higher risk of developing a zinc deficiency. If you follow a vegan or plant-based diet, you may struggle to get sufficient zinc, especially if you do not eat foods often fortified with zinc such as bread and cereal. Bariatric weight-loss surgery can impact the absorption rate of zinc and also increase the amount of zinc lost through urine. Drinking excessive amounts of alcohol can also interfere with optimal absorption of zinc.
It is important to identify and correct zinc deficiency. A lack of zinc suppresses our physical growth and development, particularly fetal growth and in early childhood. Chronic illness management can become more challenging because the lack of zinc weakens our immune defense. This increases the risk of infection and more severe symptoms. Zinc plays an important role in our reproductive systems, and a lack of zinc is often associated with fertility issues. A zinc deficiency in pregnant women can also contribute to complications such as premature birth.
A study in the US found that 42.2% of participants with Crohn’s disease and 38.6% of participants with ulcerative colitis had a zinc deficiency. The lack of zinc was associated with increased risks of being re-hospitalised and needing further surgery. There was also an increased risk of complications from the surgery itself. In this study, taking clinically prescribed zinc supplements helped to reduce these risks for the participants.
Zinc is vitally important to our reproductive functioning, enabling normal fertilisation to occur. There are between 85 and 90 times more zinc concentrations in semen, compared with blood. The reason for this is to protect sperm from bacteria, thus improving the sperm quality. A 2024 review of scientific studies found that over 50% of those taking zinc supplements alongside fertility treatment experienced subsequent fertilisation. This suggests that taking zinc supplements could improve the success rates of fertility treatment.
Pregnant or breastfeeding mothers have a higher need for zinc, and when this need is not met, problems can arise. Insufficient zinc can have various impacts on pregnancy, depending on the severity of zinc depletion. A mild zinc deficiency can result in complications during labour that lead to cesarean births. Severe zinc deficiency can increase the risk of fetal abnormalities or miscarriage. A zinc deficiency can also be passed on from mother to baby.
As with any nutrient, a healthy diet is the best way to get sufficient zinc. Zinc is a trace mineral, meaning that we need only very small daily sources of zinc via food or supplements. It is also an essential mineral. Our bodies do not organically produce zinc, nor it is stored in our bodies. With around 90% of zinc located in our muscles and bones, it follows iron as the second largest trace mineral to consume. Therefore, it is important to include daily food sources of zinc in our diet. Animal proteins such as beef, pork, and chicken are a particularly high source of zinc. Other sources include shellfish, eggs, nuts, seeds, beans, and lentils. In Western countries, common household foods such as bread, cereals, and milk are also often fortified with zinc.
In contrast to having too little zinc, it is possible to overdose on zinc, especially if taking too-high doses of zinc supplements. Some side effects of zinc over-supplementation include headaches, gastro issues (vomiting, diarrhea, nausea), and loss of appetite. Therefore, it is advisable to get tested by a health professional to determine your current zinc levels.
As always, a healthy, nutritious diet is the first step in looking after your health and making sure your body gets everything it needs. However, zinc supplements are a popular choice to prevent or correct a lack of zinc in the diet. If you are pregnant, have inflammatory bowel disease, or are experiencing infertility issues, you may be low on zinc. Appropriate testing by a health professional will inform you on whether taking zinc supplements can help support these (or other) health conditions.
