The amount of weight and force a body can use in action is relevant to nutrition. In turn, a body's weight increases the dangerousness of that body's movements. Dangerousness also increases when a person is too highly aroused for effective behavioral control. Artificial activation or allergens, which are present in many foods, affect emotions such as anger and irritability, which may in turn lead to out-of-control, dangerous behaviors. Toxins are substances which destroy tissue or directly interfere with organ function. Examples are Dioxin, PCP, and LSD as well as a host of psychotropic medications. Stress activated by toxins operates in the body to increase drive states and irritability equivalent to a reaction to sugar. Also, some nutritional substances are needed to foster effective bodily functions. The B vitamins tend to modulate some brain functions and may modify stress reactions in the body; B12 tends to increase cognitive and perceptual clarity. Zinc is probably a natural tranquilizer. Vitamin C, probably the body's most basic need, contributes to the modulation of stress.