Dietary Factors and Zinc Decrease
Inadequate dietary intake is a primary cause of low zinc levels. Since the body doesn't store zinc effectively, consistent consumption is vital. Foods like oysters, red meat, and poultry provide highly absorbable zinc.
Vegetarian and Vegan Diets
Vegetarians and vegans face a higher risk of zinc deficiency because plant foods, while containing zinc, also have phytates that inhibit absorption. Soaking, sprouting, or fermenting can reduce phytate levels.
Excessive Alcohol Consumption
Heavy alcohol use reduces zinc absorption and increases its loss through urine, often compounded by poor diet in individuals with alcohol use disorder.
Medical Conditions Affecting Zinc Absorption
Conditions affecting the gastrointestinal tract can impair zinc absorption.
Malabsorption Disorders
Diseases causing malabsorption significantly lower zinc levels. Examples include:
- Crohn's disease and celiac disease damage the small intestine, hindering nutrient uptake.
- Chronic diarrhea leads to increased zinc loss.
- Bariatric surgery limits the area for absorption.
- A rare genetic disorder, Acrodermatitis Enteropathica, prevents proper zinc absorption.
Chronic Liver and Kidney Disease
These conditions are linked to zinc deficiency due to altered metabolism and increased excretion, particularly in patients undergoing hemodialysis.
Other Chronic Diseases
Diabetes and sickle cell disease can also cause low zinc due to inflammation and increased metabolic demands.
Medications and Increased Requirements
Certain medications interfere with zinc, and some life stages or conditions increase the body's need for it.
Medications that Deplete Zinc
Drugs that can lower zinc levels include:
- Diuretics increase urinary excretion.
- Proton Pump Inhibitors (PPIs) reduce stomach acid needed for absorption.
- Antibiotics like tetracycline and quinolones can bind to zinc.
- Long-term corticosteroids use.
- Penicillamine increases urinary zinc loss.
Increased Bodily Needs
Certain conditions increase zinc demand:
- Pregnancy and lactation.
- Infancy, especially breastfed infants over six months.
- Heavy exercise and sweating.
- Severe burns.
Environmental and Agricultural Factors
Environmental factors can also impact zinc levels. Increased CO2 can lower zinc content in crops, and soil conditions affect how much zinc plants absorb. These factors contribute to deficiency in populations relying on these staple crops.
Comparative Overview of Low Zinc Causes
| Cause Category | Primary Mechanism | Affected Groups |
|---|---|---|
| Dietary | Low zinc intake, high phytate consumption | Vegetarians, vegans, malnourished individuals, people with alcohol use disorder |
| Malabsorption | Impaired intestinal absorption | Individuals with Crohn's, celiac disease, chronic diarrhea, bariatric surgery patients |
| Chronic Disease | Altered metabolism, increased excretion | Patients with liver disease, kidney disease, diabetes, sickle cell disease |
| Medications | Reduced absorption, increased excretion | People on long-term diuretics, PPIs, certain antibiotics, corticosteroids |
| Increased Needs | Higher physiological demand | Pregnant/lactating women, infants, athletes, burn patients |
Conclusion
Decreased zinc levels result from a combination of poor diet, medical conditions, and lifestyle. While dietary intake is key, malabsorption, increased losses, and medication effects are also significant factors. Those at higher risk, like vegetarians, individuals with chronic illnesses, or pregnant women, should understand these causes. Consulting a healthcare professional is essential for diagnosis and treatment. Further information is available from the National Institutes of Health Office of Dietary Supplements.
