 Oxidative damage has been shown to be a factor in Alzheimers disease AD, and some studies have suggested that supplemental anti-oxidants can decrease the risk of AD or slow its progression. There are many candidate antioxidants, including combinations, which could be neuroprotective in established AD or could have efficacy in the prevention of AD. However, testing each of the possibilities in standard clinical trials is prohibitively expensive. This study will examine antioxidant supplements or vitamins which target specific cellular compartments, and look for evidence of biologically relevant effects in AD by measurement of biomarkers in CSF. 