Zinc: Recommended Daily Intake, Factors, Risks, and Supplements

Zinc is an essential trace mineral vital for numerous bodily functions, including immune function, wound healing, protein synthesis, and DNA creation. Because the body doesn’t store excess zinc well, consistent intake through diet or supplementation is crucial. This article details recommended daily doses of zinc, factors influencing needs, potential risks, and how to choose a suitable supplement.

Recommended Daily Allowance (RDA)

The RDA for zinc varies based on age, sex, and life stage. Here’s a breakdown (values are in milligrams ー mg):

• Infants 0-6 months: 2 mg
• Infants 7-12 months: 3 mg
• Children 1-3 years: 3 mg
• Children 4-8 years: 5 mg
• Children 9-13 years: 8 mg
• Adolescent boys 14-18 years: 11 mg
• Adolescent girls 14-18 years: 9 mg
• Adult men 19+ years: 11 mg
• Adult women 19+ years: 8 mg
• Pregnant women: 11 mg
• Breastfeeding women: 12 mg

Factors Increasing Zinc Needs

Certain conditions and lifestyle factors can increase your zinc requirements:

• Vegetarian/Vegan Diets: Plant-based diets often contain phytates, which inhibit zinc absorption. Vegetarians may need up to 50% more zinc.
• Pregnancy & Breastfeeding: Increased demands to support fetal development and milk production.
• Chronic Illnesses: Conditions like diabetes, kidney disease, and Crohn’s disease can impair zinc absorption or increase excretion.
• Alcohol Consumption: Alcohol interferes with zinc absorption.
• Intense Exercise: Zinc is lost through sweat.
• Ageing: Zinc absorption tends to decrease with age.

Upper Tolerable Intake Level (UL)

While zinc is essential, exceeding the UL can be harmful. The UL for adults is 40 mg per day. Consistently exceeding this limit can lead to:

• Nausea
• Vomiting
• Loss of appetite
• Stomach cramps
• Diarrhea
• Impaired immune function
• Reduced copper absorption (leading to copper deficiency)

Choosing a Zinc Supplement

Several forms of zinc supplements are available. Absorption rates vary:

• Zinc Picolinate: Generally well-absorbed.
• Zinc Citrate: Another well-absorbed form, often preferred for its affordability.
• Zinc Gluconate: Commonly found in lozenges, may be helpful for colds.
• Zinc Sulfate: Less expensive, but can cause stomach upset in some individuals.
• Zinc Oxide: Poorly absorbed; not recommended for increasing zinc levels.

Important Considerations:

1. Dosage: Start with a lower dose and gradually increase if needed, staying within the RDA or as advised by a healthcare professional.
2. Timing: Take zinc supplements with food to minimize stomach upset.
3. Copper: Long-term zinc supplementation can lead to copper deficiency. Consider a supplement containing both zinc and copper, or ensure adequate copper intake through diet.
4. Interactions: Zinc can interact with certain medications, including antibiotics and diuretics. Consult your doctor before taking zinc supplements if you are on any medications.