A single blind placebo controlled trial was carried out to assess the effect of high dose vitamin C supplementation on the antioxidant potential, and extent of lipoprotein oxidation of serum in female smokers. Sixteen apparently healthy subjects were randomised into two groups of eight. One group received 1 g of vitamin C for 14 days the other group received a placebo for 14 days. Serum antioxidant potential (TRAP) was measured and lipoprotein oxidation was assessed by measuring serum malondialdehyde like material. Despite significant increases in serum C concentrations in the supplemented group, serum TRAP values did not change significantly over the course of the trial. Serum malondialdehyde like material also failed to show any temporal variation.