Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.
Why Vegans are Often Deficient in Vitamin B12. The few plant foods that are sources of B12 are actually B12 analogs. An analog is a substance that blocks the uptake of true B12, so your body's need for the nutrient actually increases.
Fruitarian: Eats only raw fruit, including raw nuts and seeds. Vegan. Does not eat dairy products, eggs, or any other animal product. So in a nutshell, a vegetarian diet excludes flesh, but includes other animal products: A vegan diet is one that excludes all animal products. And I have to say that I have met very few vegans who stop with what they put in their mouths.