Zinc Supplementation

Efficacy and Dosage

Zinc supplementation, administered as zinc gluconate lozenges at a dose of ≥75 mg/day, can significantly reduce the duration of common cold symptoms by approximately 2.5-3 days when taken within 24 hours of symptom onset, as recommended by the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 and supported by the American Academy of Family Physicians 1, 2
The therapeutic dose of 75 mg/day of elemental zinc has been shown to significantly reduce the duration of the common cold, with lozenges appearing to be the most studied and effective delivery method, according to the American College of Chest Physicians 2, 1

There is conflicting data on the benefit of zinc-containing compounds in treating cough due to the common cold, as noted by the American College of Physicians, CDC, and ACCP Evidence-Based Clinical Practice Guidelines 3, 4
Zinc is not recommended for treating isolated sore throat as a standalone therapy, with an evidence rating of B-2, as stated by the Infectious Diseases Society of America and supported by 5

The recommended dosage for zinc supplementation in adults for immune support during common cold is 75 mg/day of elemental zinc as zinc gluconate, as recommended by the American Academy of Family Physicians 2
For adults and children with acquired zinc deficiency, the standard dosage is 0.5-1 mg/kg/day of elemental zinc for 3-4 months, as recommended by Clinical Nutrition guidelines 6
The maximum routine supplementation dose is 5 mg/day, according to Clinical Nutrition guidelines 7
Specific dosage recommendations for different age groups include:
Patients with gastrointestinal losses or major burns may require higher doses, up to 12 mg per day or 30-35 mg/day IV, respectively, as recommended by Clinical Nutrition guidelines and ESPEN guidelines 6
Zinc supplements should be taken on an empty stomach, at least 30 minutes before meals, to maximize absorption, and avoid taking with foods high in phytates or other mineral supplements, especially iron and calcium, as recommended by the Journal of Hepatology 8

Plasma zinc levels should be measured to confirm clinical zinc deficiency and monitor adequacy of provision, with simultaneous determination of CRP and albumin required for proper interpretation, as suggested by Clinical Nutrition guidelines 6
Alkaline phosphatase levels and liver enzymes, such as serum lipase and/or amylase, should also be monitored, according to Clinical Nutrition guidelines and the Journal of Hepatology 7, 8
Common adverse effects include gastric irritation, and elevations in serum lipase and/or amylase, as reported by the Journal of Hepatology 8
Zinc toxicity can lead to copper deficiency, impaired immune function, and adverse effects on lipid profiles, and intramuscular zinc administration carries potential risks, including local irritation and pain at injection site, as stated by 9