Thirteen RCTs were included in the review: five cross-over trials and eight parallel design trials (number of participants unclear). Trial sample sizes ranged from 18 to 138 participants.
Compared with control, the vitamin C supplementation group had a statistically significantly lower net change in LDL cholesterol (net change -7.90, 95% CI -12.3 to -3.5; n=638 participants), total cholesterol (net change -10.67, 95% CI -14.0 to -7.3; n=1,119 participants) and triglycerides (net change -20.1, 95% CI -33.3 to -6.8; n=555 participants). There was a non statistically significant increase in HDL cholesterol (net change 1.1, 95% CI -0.2 to 2.3; n=692 participants).
Funnel plot assessment showed no evidence of publication bias for any of the outcomes apart from HDL cholesterol.