Vitamin C treatment reduces elevated C-reactive protein.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 18952164 · doi:10.1016/j.freeradbiomed.2008.09.030
What was done
Healthy nonsmokers (N=396) were randomized into three groups receiving 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo for 2 months. Plasma C-reactive protein (CRP), an inflammatory biomarker predicting cardiovascular disease, was measured before and after intervention.
What was found
Median baseline CRP was 0.85 mg/L across all participants. No treatment effect was observed when all participants were analyzed together. However, a significant interaction was found based on baseline CRP concentration: among participants with baseline CRP ≥ 1.0 mg/L, vitamin C reduced median CRP by 25.3% versus placebo (p=0.02), corresponding to a median reduction of 0.25 mg/L (16.7%) in the vitamin C group. Vitamin E showed no significant effect.
Why it matters
Vitamin C supplementation lowers elevated CRP to a magnitude comparable to statins, suggesting antioxidant trials should selectively enroll populations with elevated baseline biomarkers rather than unselected healthy cohorts.
Limits
The primary overall analysis showed no significant effect, with benefits restricted to subgroup and interaction analyses. The trial was limited to 2 months in healthy nonsmokers and did not assess clinical cardiovascular endpoints.
Cited by
- partial A randomized study of nearly 400 healthy adults found that daily supplementation with 1 gram of vitamin C and 800 IU of vitamin E for two months decreased C-reactive protein by nearly 17% in participants with elevated baseline CRP.