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.
Veganism is a strict type of vegetarianism that excludes meat and all animal products. Vegans do not eat meat, fish, eggs, dairy products, or any foods containing them. A vegan diet relies on plant-based foods including fruits, vegetables, grains, beans, nuts, and seeds. A vegan diet can be a healthful and nutritionally adequate diet; however, a vegan must make sure they eat enough foods with protein, calcium, iron, vitamin B12, and omega-3 fatty acids.