Metabolic functions in the body are known to be regulated. In today’s column I will discuss the regulation of body weight, blood sugar, and vitamins.

Body weight, blood sugar, and vitamins are each vital to health. Both high and low values are life-threatening. The proposal that the nervous system is designed to continuously measure and respond to blood sugar, body weight, and vitamin status makes sense to me.

Any diabetic can tell you that blood sugar levels must be maintained within a normal range. When blood sugar strays outside the normal range the effects are immediate. Unless corrected within days, blood sugar levels significantly outside the normal range are deadly. To maintain excellent health, blood sugar levels should be continuously maintained safely inside the normal range.

If I am correct, the body perceives falling blood sugar levels (and therefore fluctuating blood sugar) as an emergency. The regulatory control systems act to correct the problem. Hunger directs the body to consume easily absorbed carbohydrates, preferentially sugar. Subconscious commands direct the digestive system to accelerate the decomposition and absorption of carbohydrates. The movement of food into the colon is halted to maximize the extraction of sugars from the food already in the small intestine. Food already in the stomach is directed into the small intestine. Extra saliva, stomach acid, bicarbonate, maltase, lactase, sucrase, and amalyase are secreted.

Since controlling blood sugar is an emergency, the blood sugar control loop over-rides other control loops regulating less urgent factors. Maintaining a set weight and maintaining cellular vitamin status are obviously less urgent.

When the body perceives falling weight, hunger directs the body to consume more energy-rich food. Subconscious commands direct the digestive system to halt the movement of food into the colon. Anyone who has tried to lose a lot of weight can attest to the effectiveness of this system. As the body loses weight, hunger becomes increasingly extreme and the movement of food into the colon will literally come to a halt to ensure that every calorie consumed – even the calories in fiber – is put to use. To accomplish this task, the calories contained in fiber are shared with bacteria hosted by the digestive tract.

When the body perceives rising weight, feelings of nausea and fullness direct the body to consume less food. Subconscious commands direct the digestive system to accelerate the movement of food. Other subconscious commands direct the metabolism to speed up, causing more calories to be released to the environment as heat.

The body reacts to falling and rising vitamin levels in a similar fashion to falling weight. Hunger, fullness, and nausea direct the body to consume more or less vitamin-rich foods. Subconscious commands direct the digestive system to accelerate or halt the movement of vitamin-rich foods. The proven laxative effect of vitamin supplements supports this hypothesis.

If I’m correct, the body operates at least three independent control loops that each depend upon the use of conscious feelings to control what and how much food is eaten, and subconscious commands to the digestive tract to control secretions and food movement. Failure of any of the thousands of body parts involved (there are probably more “nervous-system” parts than “mechanical” parts) can lead to weight gain and/or other chronic health problems. One observable – weight gain – can have hundreds or thousands of different causes. With so many different causes, there can not be a single solution to the problem.

How can vitamins help? Vitamins are a necessary component of many of the tools the body uses to build an adult from an egg and sperm. Ensuring that the body has extra vitamins available in the food and supplements eaten is a good idea. Extra vitamins in the right place at the right time can reduce the number of inevitable errors that occur during growth and development. Fewer errors mean stronger, smarter, healthier adults. Extra vitamins can have healing powers. This is particularly well understood for niacin and vitamin C and has been the subject of several of my previous columns. This means extra vitamins can help with obesity by healing the broken parts I referred to above.

If I’m correct, vitamins are monitored and controlled, greatly reducing the danger of overdosing. Overdoses can cause a laxative effect, nausea, and fatigue – clear signals to reduce consumption. In the absence of these signals (or other known vitamin side effects), it is unlikely that key vitamins are doing any harm. There is much to gain, and little to lose by responsibly and knowledgably taking multivitamins along with extra vitamin C and niacin when needed.