VITAL - VITamins to Slow ALzheimer's Disease (Homocysteine Study)

Inclusion Criteria:

• National Institute of Neurological Disorders and Stroke (NINDS)/Alzheimer's Diseaseand Related Disorders Association (ADRDA) criteria for probable Alzheimer's disease.

• Mini-Mental Status Examination (MMSE) score between 14 and 26, inclusive

• Stable medical condition for 3 months

• Stable medications for 4 weeks prior to the screening visit

• Physically acceptable for this study as confirmed by medical history, physical exam,neurologic exam and clinical laboratory tests

• Supervision available for administration of study medications

• Study partner to accompany subject to all scheduled visits

• Fluent in English or Spanish

• Modified Hachinski equal to or less than 4 CT or magnetic resonance imaging (MRI)since onset of memory impairment demonstrating absence of clinically significant focallesion

• Able to complete baseline assessments

• 6 years of education or work history sufficient to exclude mental retardation

• Able to ingest oral medication

Exclusion Criteria:

• B12 or folate deficiency

• Renal insufficiency (serum creatinine >=2.0)

• Active neoplastic disease (skin tumors other than melanoma are not exclusionary;patients with stable prostate cancer may be included at the discretion of the projectdirector)

• Use of another investigational agent within 2 months

• History of clinically significant stroke

• Current evidence or history in the past 2 years of epilepsy, focal brain lesion, headinjury with loss of consciousness and/or immediate confusion after the injury, orDSM-IV criteria for any major psychiatric disorder including psychosis, majordepression, bipolar disorder, alcohol or substance abuse

• Blindness, deafness, language difficulties or any other disability which may preventthe subject from participating or cooperating in the protocol