In a randomized study of 299 older men, daily supplementation with 2 mg folate, 25 mg vitamin B6, and 400 microg vitamin B12 for a period of 2 years was found to be associated with a significantly lower increase in the amyloid beta protein 1-40 found in tangles/plaques in the brains of patients with Alzheimer's disease—as compared to subjects who received a placebo. While A beta 40 increased by an average of 18.5% (26.8pg/ml) among subjects who received a placebo, it increased by an average of only 4.9% (7.0 pg/ml) among those who received supplementation with B vitamins. The authors state, "We conclude that B vitamins may decrease the plasma level of A beta 40 and have a role in the prevention of AD."
A good multivitamin powder should have more B12 and B6 and a bit less folate, and would likely have the same effect.
"B-vitamins reduce plasma levels of beta amyloid," Flicker L, Martins RN, et al, Neurobiol Aging, 2008; 29(2): 303-5.
Jacob Teitelbaum, M.D. is one of the world's leading integrative medical authorities on fibromyalgia and chronic fatigue. He is the lead author of four research studies on their treatments, and has published numerous health & wellness books, including the bestseller on fibromyalgia and chronic fatigue syndrome From Fatigued to Fantastic! and his newer The Fatigue and Fibromyalgia Solution. Dr. Teitelbaum is one of the most frequently quoted fibromyalgia experts in the world and appears often as a guest on news and talk shows nationwide including Good Morning America, The Dr. Oz Show, Oprah & Friends, CNN, and Fox News Health.