As such, results from a 26-week randomized, double-blind, placebo- controlled study of Taiwanese AD patients given a multivitamin supplement containing vitamins B6, B12, and B9 in addition to acetylcholinesterase inhibitor treatment demonstrated a decrease in the concentration of serum homocysteine but no beneficial effects on cognition or the daily living activity of the AD patients [164]. Here, ACHE is linked to Alzheimer disease.