evidence table
Vitamin C Common Cold Meta-Analysis Evidence Table
Structured evidence table for Vitamin C Common Cold Meta-Analysis, generated from 2 reusable source documents in the Migaku knowledge base.
| topic | claim | evidence level | citation | source |
|---|---|---|---|---|
| Vitamin C Common Cold Meta-Analysis | We conducted a preliminary search of PubMed, Embase, Cochrane Library, and Web of Science databases, reviewing evidence from their inception to February 17, 2025 on the role of nutritional supplements in preventing respiratory tract infections (RTIs) among adults, with no language restrictions. | 1 | Zhu Zhixin (2025) | Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis |
| Vitamin C Common Cold Meta-Analysis | No network meta-analysis (NMA) was found that systematically compared the full range of nutritional interventions for RTI prevention. | 1 | Zhu Zhixin (2025) | Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis |
| Vitamin C Common Cold Meta-Analysis | Incorporating 107 randomized controlled trials (RCTs) with 101,751 participants, this study provides a substantially larger evidence base than previous reviews. | 1 | Zhu Zhixin (2025) | Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis |
| Vitamin C Common Cold Meta-Analysis | Eligible participants were adults aged 18 or older, taking oral nutritional supplements, and free of immune-related diseases. | 1 | Zhu Zhixin (2025) | Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis |
| Vitamin C Common Cold Meta-Analysis | 1 2 (,) 3 () Vitamin C (ascorbic acid) is a key micronutrient that is found naturally in many fruits and vegetables. | 2 | Hemilä Harri (2026) | Are the UK’s vitamin C recommendations evidence-based? A critical comment |
| Vitamin C Common Cold Meta-Analysis | 6 10 (–) 6 7 (,) 6 10 (,) This commentary focuses on the effects of vitamin C on respiratory infections and argues that strong evidence supporting the benefits of doses higher than 10 and 40 mg/d in some contexts was overlooked in the formulation of the 1991 recommendations. | 2 | Hemilä Harri (2026) | Are the UK’s vitamin C recommendations evidence-based? A critical comment |
| Vitamin C Common Cold Meta-Analysis | The study found that vitamin C deprivation (∼1 mg/d) nearly doubled the duration of colds compared with those who received 10–70 mg/d vitamin C, and the report stated that ‘such evidence as there is, however, definitely confirms the hypothesis that the absence of vitamin C tended to cause colds to last longer’; see the Supplement. | 2 | Hemilä Harri (2026) | Are the UK’s vitamin C recommendations evidence-based? A critical comment |
| Vitamin C Common Cold Meta-Analysis | It is involved in a wide range of biochemical and physiological processes, including the amidation of several peptide hormones and the synthesis of nitric oxide, norepinephrine, carnitine and collagen. | 2 | Hemilä Harri (2026) | Are the UK’s vitamin C recommendations evidence-based? A critical comment |
Source documents