*2.5. Plasma and Urine Analysis*

*Creatinine.* Urinary creatinine was determined by the Jaffe reaction using an Abbot c8000 analyser (Canterbury Health Laboratories, Christchurch, New Zealand).

*Ascorbate.* The ascorbate content of the plasma and urine was analysed using reverse-phase HPLC, with a Synergi 4 μ Hydro-RP 80A column and an ESA Coulochem II electrochemical detector, as previously described in detail [13]. In order to measure total ascorbate (reduced and oxidised), duplicate samples were reduced with tris(2-carboxyethyl)phosphine hydrochloride as described previously [22].
