Overview
- Late October 2026 testing by Öko-Test of 21 combination vitamin C and zinc supplements concluded the products offer no real added value for the healthy general population.
- The Öko-Test lab review found 13 of 21 products exceeded the German BfR’s recommended supplemental vitamin C limit and 11 exceeded the BfR-related zinc reference.
- Systematic reviews summarized by recent coverage show daily vitamin C does not cut cold incidence but can shorten symptoms by about 8 percent, and zinc taken at illness onset may shorten colds by roughly two days with low-quality evidence.
- Safety and quality concerns include digestive problems at very high vitamin C doses, long-term zinc above roughly 25 mg daily risking copper deficiency, and 10 tested products containing other flagged ingredients including five with talc.
- Experts and outlets advise getting nutrients from a balanced diet, reserving supplements for diagnosed deficiency or specific risk groups, and checking product labels and medical advice before taking higher-dose zinc or vitamin C.