The Minerals of Our Body
Minerals represent about 5 to 6 percent to total body weight in humans and function in many different ways. Some minerals such as sodium, potassium, and chloride function as electrolytes, while other minerals, such as copper, zinc, iron, chromium, selenium, and manganese can be incorporated into enzyme molecules. Also, some minerals such as calcium, phosphorus, and fluoride can play a vital structural role in strengthening bones and teeth. After water, minerals are the primary inorganic component of the body; by and large they’re the left-over (ash) after cremation of a body, as they will not combust like most organic molecules or evaporate like water.
Minerals can be broken into two broad groups based on their contribution to body weight (see Table 10.1). If a mineral accounts for more than one-thousandth of human body weight it is considered a major mineral. When a mineral accounts for less than one-thousandth of body weight it is called a minor mineral or trace mineral. Another way to designate the difference between major and minor minerals is through dietary need. The recommended dietary intake for major minerals is greater than 100 mg, while the recommendations for minor minerals are less than 100 mg. The term mineral is often used interchangeably with element, thereby indicating that all minerals are elements.
MINOR OR TRACE MINERALS
*dietary essentiality questionable despite presence in body
MAJOR MINERALS INCLUDE CALCIUM, PHOSPHOROUS,
The major minerals make up most of the mineral in our body by weight. Because of this there dietary needs are higher than miner minerals. In addition to foods, supplements make a significant contribution to many people’s intake. For instance, calcium based supplements are among the most popular with consumers who take them primarily for bone support.
What is calcium?
Without question calcium is one of the most recognizable and popular minerals. Perhaps this is well deserved, as calcium is about 40 percent of total body mineral weight and about 1.5 percent of total body weight. Furthermore, calcium tends to be portrayed as a hero for protecting the human body from osteoporosis. However, most people really do not understand how calcium functions. Calcium is found in foods and the body as an atom with a +2 charge (Ca++ or Ca2+). Calcium atoms, therefore, are most stable after they have given up two electrons (see Body Basics). Because of this heavy positive charge, calcium strongly interacts with substances bearing a negative charge. This allows it to form mineral complexes found in bone and teeth as well as interact with proteins to make things happen in certain cells.