Originally Posted by Ristaron

A buttload of energy.

B12 is only made by bacteria (plants and animals cannot synthesize it), and the human body usually has no more than 2,000-5,000 mcg (1 mg = 1,000 mcg) stored up (80% of that in the liver). It works with metabolism and the nervous system.

B6 is integral to absorbing glucose from glycogen. An overdose of B6 leads to temporary deadening of certain nerve cells, leading to a loss of proprioception (the sense of motion without effort (walking vs. riding in a car), and the position of limbs in relation to each other (such as your ability to touch your fingertips to each other when your eyes are closed)).

Frequent use of these would lead to boxing the kidney and fucking up your sense of motion.