Hi, My father was diagnosed with parkinson's with dementia 7-8 years ago and is confined to wheelchair for the past 1-1/2 years. He has been undergoing treatment for the same. He also has BP and diabetes and has been taking medicine for the same for past 20 years, both of which are completely under control. As we know that parkinson's with dementia is a progressive disease, want to know if his dementia can be treated if given B12 treatment. His B12 serum count is 303 pg/ml. He has difficulty in understanding what we speak to him and does not respond accordingly. Please advise.