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 will generally not use any product made from animals, including silk. An ovo-vegetarian will eat eggs, while a vegan will not. Cattle consume more protein in grains than they deliver in meat. A vegan won't wear any clothing made of leather, unless it's special vegan leather that's made without animal products.Vegan mayonnaise doesn't use eggs. Vegetarian meat crumbles are made of textured vegetable protein. Some vegans have an allergy or sensitivity to dairy products or avoid them for ethical reasons.vo-vegetarians will eat eggs, but not dairy. Lacto-ovo vegetarians will eat eggs and dairy products. The reasons for these choices are varied and based on individual beliefs. In some cases they are based on moral choices, and in others on dietary needs or simple preference.