1. Introduction
1.1 The Study of Minerals Is a Fragmentary View
"We have become so accustomed to the practice of dividing foodstuffs into their various nutritive factors—proteins, carbohydrates, fats, minerals, vitamins, etc.— that we often miss the importance of the whole food."
—Dr. Herbert M. Shelton
As we begin our lesson on minerals, it is important to keep Dr. Shelton's observation in mind. Phrases like "iron deficiency" and "calcium-rich foods" are all too common in the study of minerals, and they represent a fragmented view of our diet and nutritional well-being.
A mineral deficiency rarely exists by itself in a vacuum, nor can a single food be recommended exclusively because of a particular mineral content. The study of minerals by themselves necessarily leads to a fragmented view of nutrition, and the student should not be quick to attribute conditions in the body solely to a mineral deficiency, nor should he choose certain foods entirely because of their mineral content.
Instead, it is more important to realize that minerals have an interdependence between many other various elements of food and with the complex actions of the organism itself. Minerals are not isolated food factors, but parts of the nutritional whole.
1.2 What Are Minerals?
The broadest definition of a mineral is that it is something that is "neither vegetable nor animal." It has also been defined as a "solid homogeneous crystalline chemical element or compound" such as iron, copper, carbon, aluminium and so forth. For this lesson, we define a mineral as follows: A naturally occurring inorganic element in the soil which is transformed into an organic compound for use and assimilation by the human body.
Notice that there are two parts to the definition: 1) We are concerned only with those minerals that are directly usable by the human organism and that are vital to the healthy functioning of the body. 2) We make a very important distinction between the inorganic form of the mineral as it occurs in the soil and the organic form of the mineral as it is used by the human body. This difference between organic and inorganic mineral forms is the crucial point in understanding mineral nutrition, and is discussed at length later in this lesson.