Nutrients and Energy Foods
Nutrients are essential dietary factors, such as amino acids, fatty acids, minerals and vitamins. Metabolic fuels such as alcohols, carbohydrates, fats and proteins are not formally considered as nutrients. These are usually classed as energy fuels. However, this practice is not always adhered to, and one can read in nutrition literature references to fats and carbohydrates as nutrients.
There are two kinds of nutrient lists of interest to the average consumer. One, is the nutrients contained in foods, given in specialized publications on diet or nutrition, where the carbohydrate protein, fat and a variety of vitamins and minerals are duly recorded in grams per 100 gram weight. The other, is the Recommended Daily Allowances (RDAs) various governments currently demand to be placed on the package of foods offered for public consumption. Both these have serious limitations and require some comments.
Some specialized publications record the maximum of nutrients and in the case of fruits and vegetables, these of the fresh products. Others record averages. The problem is that the consumer hardly ever gets to eat such products. Water soluble vitamins such as the Bs and C in particular, begin to be dissociated shortly after the fruit or vegetable has been cut. So for example, a fresh orange may have up to 180mg of vitamin C, but a supermarket orange that looks just as fresh, may have nothing left of the same vitamin. The provitamin A of carrots was found to range from 70 to 18,000 International Units (IU), while the vitamin E of wheat germ from 3.2 to 21 IU. The selenium content of crops in the US is known to vary by a factor of 200, and so on and on.
Looking up the nutrient value of a food under these circumstances, is no more than an exercise in futility. It is not even worth the effort of turning the pages of a book. Don't try it, unless you are reasonably sure that what you buy is fresh, and not just looks fresh.
The Recommended Daily Allowances on the other hand, are inadequate in the best of circumstances. They were not designed to provide a healthy amount of vitamins and minerals, or even a tolerably average intake of these nutrients. Something that would be hard to do in any case, since most people have, if not unique nutrient requirements, certainly different enough from the next person to render averages totally inadequate. RDAs were designed mostly as deficiency averting minima. In other words, amounts known to counteract specific deficiencies. But there is a world of difference between a person whose nutrition just manages to avoid deficiencies, and the same person under a regimen designed to provide the best nutrient balance possible.
The nutrients we need
Briefly, we would not need to take nutrient supplements, if our nutrition was the same as that of our ancestors. Unfortunately, it isn't; not by any stretch of the imagination. Neither our soils, nor our water, atmosphere, or the plant products themselves are quite the same. Neither is the meat of animals feeding on such plants, to say nothing of the antibiotics, growth and other hormones, etc, fed or injected in such animals. To put it mildly, our food resources and nutrition bases are compromised. And the only way we can be certain of obtaining the nutrients we need, is by taking regular supplements.
Of course, if the supplements we take are these we need, is altogether another story. For this we must be aware of a person's specific traits, such as blood group, ancestry, hereditary disposition, normal diet, past and present medical status, recent injuries, food allergies, but also of nutrient-nutrient interaction, nutrient-food interaction, and in case of drug therapy, nutrient-drug interaction. We should also know this person's regime of physical exercise, any athletic performance, pregnancy or lactation in women, and any debilitating injuries or serious ailments of the liver, pancreas and kidneys. For a personalized Vitamin and Mineral profile, see Services - Customized Programs.