False: Vitamin B12 is made by neither animals nor plants, but by microbes. This is another reason why its important to support your gut’s “good bacteria.” Vitamin B12 deficiency is common in vegans who don’t eat B12 fortified foods or take B12 supplements and can result in paralysis, myelopathy, psychosis, or atherosclerosis. A plant-based diet may improve Alzheimer’s symptoms, but if without B12 supplementation, a plant-based diet may make things worse. It is imperative that those eating plant-based diets include B12-fortified foods in their diet or take B12 supplements, especially pregnant or nursing women. Testing is not necessary, but supplementing is—it may even increase one’s lifespan.