Dementia, Alzheimers and more can be battled with proper B vitamins.  This article is from Dr. Mercola, but I buy Solgar brand B vitamins.  I will be honest with you, I did have a stroke in 2019 but it was so mild I didn't even know I'd had it and I was only in the hospital for 2 days, I can still drive and do everything I always did.  I lost partial vision in my right eye but it's really not an issue most of the time.  I credit some of the non-severity of that stroke to my lifestyle, which includes very few vitamins, just the ones I deem most important FOR ME.  Everyone is different, of course.

I take these 3 B vitamins (Solgar brand B6, B9 *folate, and B12 which is sublingual) along with D3 and K2 for my BONES and my muscle structure more than anything.  But hey, if it helps other stuff at the same time, more's the better, right?!!

https://articles.mercola.com/sites/articles/archive/2022/04/19/b-vitamins-cognitive-function.aspx

A direct quote from the article at the link above.  "Vitamins B6, B9 (folate) and B12 may be particularly important for supporting cognitive function as you age."