Zinc is a micronutrient that is vital to the body’s immune system. This mineral helps the immune system and metabolism function in several different roles, mainly helping to regulate how insulin is used to help manage blood sugar. Zinc is also vital to the immune system, as it helps cells develop and function, which helps keep our immune systems strong and more able to fight off infections. Another central role zinc plays in the body is to help with wound healing. This is because zinc is needed for collagen and protein synthesis, which speeds up tissue regeneration after an injury to the skin. Finally, zinc is also necessary for body growth and development, as it plays a vital role in cell growth and division.

Since this mineral has so many important jobs in our body, we must have plenty of it every day. Our bodies do not store large amounts of zinc, which means we need to obtain it from the food we eat or add a supplement to meet our needs. Our body also does not produce zinc, meaning it is an essential nutrient. Since they don’t contain it naturally, many foods have added zinc, such as cereal and granola bars. Zinc is found naturally in plant and animal foods, though meat and seafood are among the highest. The highest amounts of zinc are found in foods such as red meat, poultry, beans, lobster, pumpkin seeds, and dairy. Interestingly, oysters contain the highest amount of zinc per serving (twice as much as a serving of steak!). Eating a well-balanced diet can help ensure you meet your needs daily.

The recommended dietary allowance (RDA) for zinc is 11mg daily for men and 8mg daily for women. Pregnant and lactating women need closer to 12mg daily since zinc is important for fetal growth and development. Most people in the US consume plenty of zinc, though some populations are more at risk for deficiency. This includes older adults, mainly due to lower overall food intake; people who don’t eat meat or animal products, as these are the richest sources of zinc; children who are choosy eaters; and diseases of the gut, as the body may have difficulties absorbing nutrients, such as in Crohn’s or colitis.

As with other nutrients, deficiency of zinc also occurs commonly in patients who have had bariatric surgery. This is because bariatric surgery reduces a person’s overall food intake and changes the body’s ability to digest and absorb food. Moreover, many patients have a zinc deficiency even before weight loss surgery. While the exact percentage isn’t known, many doctors estimate this to be in 10-50% of people undergoing surgery. This is why eating a balanced diet after surgery is so important – the plate method (make half your plate fruits and vegetables, ¼ complex carbs, and ¼ protein) is an excellent way to ensure optimal nutrient intake every day.

A doctor can diagnose zinc deficiency through blood, urine, or hair samples. This test will typically occur only if signs and symptoms of deficiency are present. These signs include hair loss, changes in nail texture, lower desire for food, slow-healing wounds, diarrhea, and cold symptoms. Often, doctors will prescribe a zinc supplement and see if this improves symptoms.

Many researchers believe that zinc can help reduce the severity and duration of the common cold. This is thought to be due to zinc’s role in reducing inflammation throughout the body, especially in the sinuses. While this research is not entirely conclusive (some studies show it helps, but possibly only in people who are deficient), it’s important to ensure you eat plenty of healthy foods when you’re sick. This also includes a diet high in vitamin C since it’s also crucial for the immune system’s health.

Zinc plays many important roles in the body, so it’s vital that both kids and adults consume enough of it daily, but bariatric surgery can make it especially difficult to get enough of this nutrient. Still, a healthy diet (and possibly a zinc supplement) can reduce the risk of developing a deficiency and keep you healthy following surgery. As always, discussing zinc needs with a health professional (dietitian, doctor, or another practitioner) is essential following bariatric surgery.

References:

1. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc Washington, DC: National Academy Press; 2001.
2. MacDonald RS. The Role of Zinc in Growth and Cell Proliferation. The Journal of Nutrition 2000;130:1500S-8S. [PubMed abstract]
3. Hennigar SR, Lieberman HR, Fulgoni VL, 3rd, McClung JP. Serum Zinc Concentrations in the US population are related to sex, age, and time of blood draw but not dietary or supplemental zinc. J Nutr 2018;148:1341-51. [PubMed abstract]
4. King JC, Brown KH, Gibson RS, Krebs NF, Lowe NM, Siekmann JH, et al. Biomarkers of Nutrition for Development (BOND)-Zinc Review. J Nutr 2015;146:858S-85S. [PubMed abstract]
5. World Health Organization, Food and Agriculture Organization. Vitamin and Mineral Requirements in Human Nutrition . World Health Organization and Food and Agriculture Organization of the United Nations, 2004.
6. Brnic M, Wegmuller R, Melse-Boonstra A, Stomph T, Zeder C, Tay FM, et al. Zinc absorption by adults is similar from intrinsically labeled zinc- biofortified rice and from rice fortified with labeled zinc sulfate. J Nutr 2016;146:76-80. [PubMed abstract]
7. Wegmuller R, Tay F, Zeder C, Brnic M, Hurrell RF. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide. J Nutr 2014;144:132-6. [PubMed abstract]
8. Doherty K, Connor M, Cruickshank R. Zinc-containing denture adhesive: a potential source of excess zinc resulting in copper deficiency myelopathy. Br Dent J 2011;210:523-5. [PubMed abstract]

Chloe Seddon is a registered dietitian nutritionist who holds a Master’s Degree in health promotion from the University of Connecticut. She specializes in nutritional counseling, with a focus on a non-dieting approach to maintain healthy weight and goal-oriented lifestyle changes for long term success. She teaches intuitive eating and easy meal preparation to help clients sort through the myriad of nutritional misinformation to focus on having a balanced and happy relationship with food. She counsels clients with a range of issues, including chronic disease management, sports nutrition, disordered eating and weight loss. Chloe currently works as a nutritional counselor and educator providing group and individual consulting. She believes that balancing food, eating and exercise should be enjoyable and healthful.