Inclusion Criteria:  Adults (>18 years) with a functioning (not on dialysis) kidney transplant. More than 12 months post-transplant. Able and willing to give informed consent. Skin Autofluorescence levels above the general population mean value for age.  Exclusion Criteria:  Persons with dark skin colour (i.e. Fitzpatrick skin colour type 5-6). Persons with malnutrition (Subjective Global Assessment [SGA] score <5). Pregnancy or breast feeding or intending pregnancy. Active infection. Active rejection. Persons with learning difficulties. Prisoners.