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.
A vegan diet is one that eliminates all animal products and focuses only on plant-based foods. That not only means no meat, but also means no dairy and no eggs. Most vegans also try to avoid processed animal products, like gelatin, that sometimes get added to foods that seem like they would otherwise be vegan. Because the diet is low in calories, cholesterol and saturated fat, going vegan tends to help with weight loss and helps normalize your cholesterol and blood pressure. While more and more restaurants are offering vegan options, it can be hard to find a place to eat out in some parts of the country.