What is the reason for zinc deficiency?

December 17, 2025 •

4 min read

According to conservative estimates, up to 25% of the world's population is at risk for zinc deficiency, making it a widespread nutritional concern. This essential mineral is required for numerous bodily functions, and its deficiency can be attributed to various factors, ranging from inadequate dietary intake to underlying health issues.

Quick Summary

Zinc deficiency is caused by insufficient dietary intake, poor absorption due to medical conditions, or increased bodily loss of the mineral. Several factors can affect an individual's zinc levels, including diet, age, and existing gastrointestinal problems.

Key Points

Dietary Factors: The most common reason for zinc deficiency is not eating enough zinc-rich foods, a risk increased by vegetarian or vegan diets and high intake of phytates.
Malabsorption Conditions: Gastrointestinal diseases like Crohn's disease, celiac disease, and chronic diarrhea disrupt the body's ability to absorb zinc, even if enough is consumed.
Increased Loss: Chronic alcoholism, intense exercise, and conditions like burns and liver or kidney disease cause the body to excrete more zinc than normal.
Heightened Requirements: Pregnant and lactating women, as well as rapidly growing infants and children, have an increased need for zinc that can lead to deficiency if intake is not sufficient.
Inhibitory Substances: Phytates found in whole grains and legumes, along with excessive supplemental iron or calcium, can significantly inhibit zinc absorption.
Genetic Factors: A rare hereditary disorder called Acrodermatitis Enteropathica causes a severe, lifelong zinc malabsorption issue that requires supplementation.

The Primary Causes of Zinc Deficiency

Zinc deficiency can result from several interconnected factors, with the most common being insufficient dietary intake. Since the body cannot store large amounts of zinc, a regular supply is crucial to maintaining adequate levels. However, other physiological and pathological reasons can also contribute to low zinc status.

Inadequate Dietary Intake

Diet plays a critical role, and certain dietary patterns can significantly increase the risk of developing a zinc deficiency. A balanced diet should include a variety of zinc-rich foods, and disruptions to this intake are a leading cause.

Low Consumption of Zinc-Rich Foods: Diets lacking in sources like meat, seafood (especially oysters), nuts, and seeds are often low in zinc. This is a particular concern for individuals in regions with limited access to these foods.
Vegetarian and Vegan Diets: Plant-based diets, while healthy, can pose a challenge. Zinc from plant sources like legumes and whole grains is less bioavailable than from animal products. This is because of compounds called phytates found in these foods.
High Phytate Consumption: Phytates bind to zinc in the digestive tract, inhibiting its absorption. Vegetarians and vegans who consume high amounts of whole grains, legumes, and seeds without proper preparation (like soaking or sprouting) are at a higher risk.
Excessive Alcohol Consumption: Chronic alcoholism can lead to zinc deficiency by reducing absorption and increasing the amount of zinc excreted through urine.

Malabsorption and Underlying Medical Conditions

Even with a diet rich in zinc, certain medical conditions can interfere with the body's ability to absorb and utilize the mineral effectively. These health issues disrupt the digestive process or alter mineral metabolism.

Gastrointestinal Disorders: Conditions that affect the small intestine, where nutrient absorption occurs, are major culprits. These include:
- Crohn's Disease: A type of inflammatory bowel disease that causes chronic inflammation of the digestive tract.
- Celiac Disease: An autoimmune disorder where consuming gluten leads to damage in the small intestine.
- Ulcerative Colitis: Another inflammatory bowel disease that causes long-lasting inflammation in the large intestine.
Chronic Diseases: Kidney disease and chronic liver disease can interfere with zinc metabolism and increase its loss from the body. Diabetes mellitus has also been linked to lower zinc levels.
Genetic Disorders: The rare hereditary condition, Acrodermatitis Enteropathica, is caused by a genetic defect that impairs zinc absorption from the intestine.
Bariatric Surgery: Procedures like gastric bypass can reduce zinc absorption due to changes in the digestive tract.

Increased Loss or Requirement

In certain life stages or medical situations, the body's demand for zinc increases or its loss is accelerated, leading to a deficiency if not properly managed.

Pregnancy and Lactation: Pregnant and breastfeeding women have a higher zinc requirement to support the growing fetus or infant. Insufficient intake during these periods can lead to deficiency for both mother and child.
Chronic Diarrhea: This condition leads to the excessive excretion of zinc from the body, making it a significant cause of deficiency, especially in children in developing countries.
Intense Exercise: Strenuous physical activity can increase zinc loss through sweat and urine, potentially affecting athletes if dietary intake is insufficient.
Severe Burns: Extensive skin burns can cause a significant loss of zinc from the body.

Medical vs. Dietary Factors in Zinc Deficiency


Factor	Dietary-Based Zinc Deficiency	Medically-Induced Zinc Deficiency
Primary Cause	Insufficient intake of zinc-rich foods, high phytate intake, or restrictive diets.	Impaired absorption, increased excretion, or heightened demand due to a specific health condition.
Onset	Often gradual, developing over time due to consistent dietary patterns.	Can be sudden or gradual, depending on the underlying condition (e.g., rapid onset after bariatric surgery or weaning in genetic cases).
Population Affected	Vegetarians, vegans, older adults, and individuals with poor overall nutrition.	People with gastrointestinal disorders, chronic diseases, alcohol use disorder, or those undergoing specific medical treatments.
Dietary Impact	Directly linked to food choices and the bioavailability of zinc in the diet.	Can occur even with a seemingly adequate diet due to internal processing problems.
Typical Treatment	Dietary modifications, such as increasing zinc-rich foods, and supplementation.	Addressing the underlying medical condition, alongside tailored dietary adjustments and supplements, often requiring medical supervision.

Conclusion

Identifying the root cause of low zinc levels is crucial for effective treatment, as a one-size-fits-all approach is not appropriate. While inadequate dietary intake is a major contributor, especially for those on plant-based diets or with poor nutrition, a variety of medical conditions can also be responsible for malabsorption or increased bodily loss. For vulnerable groups like pregnant women, children, and those with chronic diseases, proactive monitoring and intervention are essential. Anyone suspecting a zinc deficiency should consult a healthcare provider to determine the specific reason and receive the most appropriate treatment plan.

For more in-depth information, the NIH Office of Dietary Supplements offers a comprehensive fact sheet on Zinc.

Frequently Asked Questions

The most likely dietary factors include insufficient intake of zinc-rich foods like meat, seafood, nuts, and seeds. Vegetarian and vegan diets can also cause deficiency because plant-based zinc is less bioavailable due to compounds called phytates found in grains and legumes.

Yes, high intake of phytates, which are found in large amounts in whole grains, legumes, and seeds, can cause a zinc deficiency by binding to the mineral and preventing its absorption. Vegetarians and vegans who rely heavily on these foods are at particular risk.

Several medical conditions can cause zinc deficiency, including gastrointestinal disorders like Crohn's disease, celiac disease, and ulcerative colitis. Chronic liver or kidney disease, alcoholism, and diabetes can also disrupt zinc levels.

Pregnant and breastfeeding women have a higher zinc requirement to support the developing fetus or infant. If their dietary intake is not sufficient to meet this increased demand, they can become deficient.

Yes, chronic alcohol use is a risk factor for zinc deficiency. It decreases zinc absorption from the diet and increases its excretion through the kidneys, leading to lower levels in the body.

Some medications can affect zinc levels. Diuretics, for example, can increase the urinary excretion of zinc. Some antibiotics and penicillamine can also interfere with zinc absorption.

Yes, it is possible. Underlying medical issues like malabsorption disorders (e.g., celiac disease) can prevent the body from absorbing zinc properly, regardless of dietary intake. Increased bodily loss due to chronic diarrhea or other conditions can also cause a deficiency.