How to recognize the symptoms of zinc deficiency and the best ways to add more zinc to your diet

del mar columbus — Oysters are a great source of zinc with 74 mg per serving.
Del Mar SoCal Kitchen/Facebook

Common signs and symptoms of a zinc deficiency include canker sores, deformed nails, hair loss, and rashes.
About one-third of the global population is considered to have a zinc deficiency, making this a common problem.
To treat a zinc deficiency, you should increase your dietary intake by consuming oysters or pork chops, or try supplements if your doctor recommends them.
This article was medically reviewed by Samantha Cassetty, MS, RD, nutrition and wellness expert with a private practice based in New York City.
Visit Insider’s Health Reference library for more advice.

Zinc is an essential mineral that our bodies need to maintain important processes like the immune system and metabolism. About one-third of people worldwide are deficient in this essential mineral. Without enough of it, people can experience symptoms like low libido and a reduced sense of smell.

Here’s what you need to know about the signs and symptoms of zinc deficiency, and how you can incorporate more of this mineral into your diet.

What does zinc do?

Zinc plays an important role in the development and functioning of our bodies, including:

Supports growth and development: Zinc is important for cell growth and division. It is required during fetal development, infancy, and childhood. Zinc supplementation during pregnancy decreases the likelihood of premature birth as well as infant and childhood illness and mortality. It’s estimated that over 80% of pregnant women worldwide don’t meet the daily recommended doses of zinc.
Boosts immune function: Zinc is known to improve symptoms of common colds, and is even found in many over-the-counter cold medications. It works by “binding to viruses in a way that prevents them from getting into our cells,” says Robin Foroutan, an integrative dietitian and spokesperson for the Academy of Nutrition and Dietetics. Zinc also blocks viruses from replicating and plays a role in wound healing and tissue repair.
Facilitates biochemical reactions: Maintaining a constant level of zinc is necessary for your body to function as it drives many metabolic reactions, like the ability of small intestines to digest food. In fact, zinc is required for over 300 chemical reactions to take place in the body, says Elad Tako, an associate professor in the Department of Food Science at Cornell University.

Signs and symptoms of zinc deficiency

Symptoms of a zinc deficiency can vary from person to person, since the mineral plays a role in a wide variety of bodily functions.

Symptoms for mild cases of zinc deficiency include:

Canker sores
Dulled sense of taste or smell
Low libido in men
Deformed nails
Poor wound healing
Hair loss
Rough skin or rashes

According to Foroutan, severe zinc deficiency can cause symptoms like:

Cognitive impairment
Frequent infections
Stunted growth in children and adolescents
Hypogonadism in males, which is when the body doesn't produce enough testosterone
Skin lesions

Causes of zinc deficiency

Normal zinc levels in the blood are between 0.66 to 1.10 mcg/mL. A zinc deficiency occurs when zinc levels in the blood drop below that range. This can happen if you consume less than your recommended daily intake.

The daily recommended dietary allowance (RDA) for zinc is:

Life Stage	Age	Males (mg/day)	Females (mg/day)
Infants	0-6 months	2	2
Infants	7-12 months	3	3
Children	1-3 years	3	3
Children	4-8 years	5	5
Children	9-13 years	8	8
Adolescents	14-18 years	11	9
Adults	19 years and older	11	8
Pregnancy	18 years and younger	-	12
Pregnancy	19 years and older	-	11
Breast-feeding	18 years and younger	-	13
Breast-feeding	19 years and older	-	12

Some groups of people are at an increased risk of zinc deficiency, like those with:

Alcoholism
Irritable bowel syndrome (IBS)
Malabsorption syndromes – which make it difficult for the intestines to absorb nutrients
Acrodermatitis enteropathica — a rare genetic disease that prevents people from absorbing zinc properly

Kelly Jones, MS, RD, CSSD, a registered dietitian based in Pennsylvania, says that people who follow strict vegan or vegetarian diets may also be at an increased risk for zinc deficiency. This is because phytic acid — a natural substance found in plants and seeds — can bind to zinc and may reduce zinc absorption.

Eating too much fiber can also reduce zinc absorption. "This is why it's important to get fiber from whole plant foods in moderate doses instead of the large doses in most fiber supplements and fortified packaged fiber products," says Jones.

Diagnosis

If you are experiencing any symptoms of zinc deficiency, go to the doctor or consult a dietitian. They will order either a blood, urine, or hair test to determine the zinc levels in your body.

"Even if it's just frequently catching colds, it's important to see your doctor for evaluation," says Jones. "If it's not a zinc deficiency, it could be caused by low intake of a variety of other nutrients."

Zinc deficiency treatment

Depending on the cause of your zinc deficiency, your doctor may recommend dietary changes and potentially zinc supplementation.

"There are multiple physiological and other, such as dietary, reasons that may lead to a zinc-deficient status, so it is important to consult with your doctor in order to determine the best and specific treatment options," says Tako.

Supplements

Once diagnosed, your doctor may prescribe a zinc supplement that is two to five times the recommended daily amount of zinc for up to six months. The upper limit intake level of zinc is 40 mg per day for adults and 4mg per day for infants under six months old. More than that amount can cause negative consequences like stomach, kidney, or liver problems. That's why you should always consult with your doctor before taking any type of supplement.

People that have experienced brain conditions or injuries, such as seizures, epilepsy, or strokes, should not take zinc supplements, says Samba Reddy, PhD, RPh, a professor in the Department of Neurosciences and Experimental Therapeutics at Texas A&M University. That's because they are more likely to have a weakened blood-brain barrier, meaning zinc can more easily enter the brain, causing an increased risk of seizures.

Diet

You can also increase zinc levels by consuming more through your diet. Here are some examples of foods that are rich in zinc:

Oysters: 74mg
Beef: 7mg
Alaskan king crab: 6.5mg
Pork chops: 2.9mg

Insider's takeaway

A zinc deficiency occurs when you are not consuming enough zinc through your diet or have an underlying health condition like alcoholism or IBS that makes it difficult for your body to absorb. Common symptoms of a zinc deficiency include canker sores, hair loss, skin rashes, and slow wound healing. However, a deficiency can be treated through monitored supplementation and by increasing your dietary intake of the mineral.