Vitamin C in doses as high as one gram daily for several winter months , had no consistent beneficial effect on incidence of the common cold .
For both preventive and therapeutic trials , there was a consistently beneficial but generally modest therapeutic effect on duration of cold symptoms .
There was no clear indication of the relative benefits of different regimes or vitamin C doses .
However in trials that tested vitamin C after cold symptoms occurred , there was some evidence that a large dose produced greater benefits than lower doses .
REVIEW ER 'S CONCLUSIONS Long term daily supplementation with vitamin C in large doses daily does not appear to prevent colds .
BACKGROUND The role of oral ascorbic acid ( vitamin C ) in the prevention and treatment of colds remains controversial despite many controlled trials .
There have also been a number of efforts to synthesize and /or overview the results of these trials , and controversy over what these overviews tell us .
OBJECTIVES The objective of this review was to answer the following two questions : ( 1 ) Does regular high dosage supplementation with vitamin C reduce the incidence of colds ? (
2 ) Does taking vitamin C in high doses at the onset of a cold have a therapeutic effect ?
Does multivitamin supplementation prevent infections in healthy elderly subjects? A controlled trial.
We performed a double blind r and omized study in order to assess the efficacy of a multivitamin supplement for the prevention of common infections in healthy elderly subjects . Non-institutionalized , independent subjects over 60 years of age , living in the Nevers area ( central France ) were recruited by announcements and r and omly assigned to a treatment or a placebo group . The treatment or placebo tablets were to be taken daily for 4 months . The principal criterion of response was the incidence of infections , as recorded from a detailed question naire presented at entrance , in the middle ( 2 months ) and at the end ( 4 months ) of the study . Blood sample s were taken at the entrance in the study and after two and four months in order to monitor vitamin status . No significant difference was found between the two groups for the incidence of infections . In fact the observed incidences during the two two-month periods were higher in the treatment ( 0.38 and 0.21 ) than in the placebo group ( 0.29 and 0.13 ) . After two months and after four months of supplementation , blood vitamin indicators of the subjects were significantly higher in the treatment than in the placebo group for vitamins B1 , B2 , B6 , E and folates ( p < 0.001 ) . The improvement of the vitamin C status was slightly higher in the treatment than in the placebo group . For vitamin A status , the evolution was similar in the two groups . In conclusion , short-term supplementation of healthy elderly subjects with the investigated supplement is not likely to afford a meaningful protection against common infections
Vitamin C in doses as high as one gram daily for several winter months , had no consistent beneficial effect on incidence of the common cold .
For both preventive and therapeutic trials , there was a consistently beneficial but generally modest therapeutic effect on duration of cold symptoms .
There was no clear indication of the relative benefits of different regimes or vitamin C doses .
However in trials that tested vitamin C after cold symptoms occurred , there was some evidence that a large dose produced greater benefits than lower doses .
REVIEW ER 'S CONCLUSIONS Long term daily supplementation with vitamin C in large doses daily does not appear to prevent colds .
BACKGROUND The role of oral ascorbic acid ( vitamin C ) in the prevention and treatment of colds remains controversial despite many controlled trials .
There have also been a number of efforts to synthesize and /or overview the results of these trials , and controversy over what these overviews tell us .
OBJECTIVES The objective of this review was to answer the following two questions : ( 1 ) Does regular high dosage supplementation with vitamin C reduce the incidence of colds ? (
2 ) Does taking vitamin C in high doses at the onset of a cold have a therapeutic effect ?