Some studies have shown that those on a plant-based diet are found to have lower plasma vitamin B12 levels and higher levels of vitamin B12 deficiency than those who consume animal products. Vitamin B12 is an important cofactor in DNA synthesis, and deficiency can lead to anemia and severe neurological dysfunction.

Unfortunately, due to the highly restrictive nature of the diet, vegans are at risk of being deficient in certain nutrients such as calcium and vitamin B12 usually found in dairy and meat respectively.

Vegetarians and vegans typically have lower body mass index, serum low-density lipoprotein (LDL) cholesterol and blood pressure than comparable regular meat-eaters, as well as lower bone mineral density.