Recent studies demonstrated efficacy of a vitamin/ nutriceutical formulation (folate, vitamin B12, alpha-tocopherol, S-adenosyl methionine, N-acetyl cysteine, and acetyl-L-carnitine) for mild to moderate Alzheimer's disease. Herein, we tested the efficacy of this formulation in a small cohort of 12 institutionalized patients diagnosed with moderate-stage to later-stage Alzheimer's disease. Participants were randomly separated into treatment of placebo groups. Participants receiving the formulation demonstrated a clinically significant delay in decline in the Dementia Rating Scale and clock-drawing test as compared to those receiving placebo. Institutional caregivers reported approximately 30% improvement in the Neuropyschiatric Inventory and maintenance of performance in the Alzheimer's Disease Cooperative Study-Activities of Daily Living for more than 9 months. This formulation holds promise for delaying the decline in cognition, mood, and daily function that accompanies the progression of Alzheimer's disease, and may be particularly useful as a supplement for pharmacological approaches during later stages of this disorder. A larger trial is warranted.