Worsened Parkinson's Disease with Low B 12

   Folks with early untreated Parkinson's disease with low vitamin B12 (less than 157 pmol/L) were found to have greater worsening of mobility and cognitive decline over time.
  Further, elevated homocysteine predicted greater cognitive decline.
Mov Disord. 2018 Mar 6

Eat Your Nicotine Containing Veggies and Decrease Parkinson's Risk

  In a population based study of 490 newly diagnosed patients with Parkinson's disease and 644 healthy controls, patients that consumed fruits and vegetables that contain nicotine ie. from the same botanical family as tobacco, Solanaceae, including peppers (especially peppers), tomatoes and potatoes.
Annals of Neurology May 9, 2013