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.

topicclaimevidence levelcitationsource
Vitamin C Common Cold Meta-AnalysisWe 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.1Zhu 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-AnalysisNo network meta-analysis (NMA) was found that systematically compared the full range of nutritional interventions for RTI prevention.1Zhu 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-AnalysisIncorporating 107 randomized controlled trials (RCTs) with 101,751 participants, this study provides a substantially larger evidence base than previous reviews.1Zhu 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-AnalysisEligible participants were adults aged 18 or older, taking oral nutritional supplements, and free of immune-related diseases.1Zhu 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-Analysis1 2 (,) 3 () Vitamin C (ascorbic acid) is a key micronutrient that is found naturally in many fruits and vegetables.2Hemilä Harri (2026)Are the UK’s vitamin C recommendations evidence-based? A critical comment
Vitamin C Common Cold Meta-Analysis6 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.2Hemilä Harri (2026)Are the UK’s vitamin C recommendations evidence-based? A critical comment
Vitamin C Common Cold Meta-AnalysisThe 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.2Hemilä Harri (2026)Are the UK’s vitamin C recommendations evidence-based? A critical comment
Vitamin C Common Cold Meta-AnalysisIt 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.2Hemilä Harri (2026)Are the UK’s vitamin C recommendations evidence-based? A critical comment
topicVitamin C Common Cold Meta-Analysis
claimWe 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.
evidence level1
citationZhu Zhixin (2025)
sourceComparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis
topicVitamin C Common Cold Meta-Analysis
claimNo network meta-analysis (NMA) was found that systematically compared the full range of nutritional interventions for RTI prevention.
evidence level1
citationZhu Zhixin (2025)
sourceComparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis
topicVitamin C Common Cold Meta-Analysis
claimIncorporating 107 randomized controlled trials (RCTs) with 101,751 participants, this study provides a substantially larger evidence base than previous reviews.
evidence level1
citationZhu Zhixin (2025)
sourceComparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis
topicVitamin C Common Cold Meta-Analysis
claimEligible participants were adults aged 18 or older, taking oral nutritional supplements, and free of immune-related diseases.
evidence level1
citationZhu Zhixin (2025)
sourceComparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis
topicVitamin C Common Cold Meta-Analysis
claim1 2 (,) 3 () Vitamin C (ascorbic acid) is a key micronutrient that is found naturally in many fruits and vegetables.
evidence level2
citationHemilä Harri (2026)
sourceAre the UK’s vitamin C recommendations evidence-based? A critical comment
topicVitamin C Common Cold Meta-Analysis
claim6 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.
evidence level2
citationHemilä Harri (2026)
sourceAre the UK’s vitamin C recommendations evidence-based? A critical comment
topicVitamin C Common Cold Meta-Analysis
claimThe 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.
evidence level2
citationHemilä Harri (2026)
sourceAre the UK’s vitamin C recommendations evidence-based? A critical comment
topicVitamin C Common Cold Meta-Analysis
claimIt 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.
evidence level2
citationHemilä Harri (2026)
sourceAre the UK’s vitamin C recommendations evidence-based? A critical comment

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Source documents

  1. Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis
  2. Are the UK’s vitamin C recommendations evidence-based? A critical comment