Here are some examples of nutrients essential for specific body functions. These nutrients provide "information" so the body can complete the necessary processes. (Note: This is a simplification for illustrative purposes. There are no doubt many more substances involved in all of these processes, including trace minerals and co-factors.)
Immune function: vitamin A, vitamin E, zinc, folic acid, vitamin B-6, riboflavin, magnesium, selenium, vitamin C
Nerve impulses: sodium, potassium, magnesium, calcium, vitamin B6, folic acid, B-12, copper, vitamin C
Tissue repair and formation: vitamin A, vitamin E, copper, riboflavin, magnesium, vitamin B6, vitamin C
Metabolism: potassium, thiamin, niacin, vitamin B6, magnesium, riboflavin, folic acid, vitamin C
Note that magnesium is needed for all of the functions listed above. Let's take a closer look at magnesium as "information."
Magnesium is a mineral found in whole grain, wheat germ, nuts, and seeds (especially pumpkin seeds), soybeans, tofu, chocolate, dark-green vegetables, legumes, yogurt, and other dairy products. However, the amount of magnesium in any magnesium-rich food is influenced by the soil content in which the food was grown. In many commercial farms, magnesium has been depleted from the soil.
If a person did not get enough magnesium over a period of time, these functions would decline. The magnesium insufficiency might manifest as the following:
Eating magnesium-rich foods or supplementing with magnesium would provide the information needed to restore function and reduce risk.
Links:
[1] http://www.takingcharge.csh.umn.edu/explore-healing-practices/food-medicine/how-does-food-impact-health