Nutritional minerals in food are elements, also known as atoms, and you can find them in the Periodic Table of the Elements (below).
Elements are made up of protons and neutrons that reside in a central nucleus. They also have electrons that orbit the nucleus in shells similar to the layers of an onion; also kind of like satellites that orbit the earth at different altitudes.
The number of electrons in the outermost orbit of the atom is what determines how stable they are and how they combine with other atoms to form compounds.
A calcium atom has 20 protons which is what makes it calcium. Similarly oxygen's 8 protons and carbons 6 protons is what gives them their unique identity. The number of protons in an atomic nucleus is what determines the element.
Vitamins are not elements, they are compounds; meaning they are made up of a collection of different atoms. For example, vitamin C is made up of 8 hydrogen atoms, 6 oxygen atoms and 6 carbon atoms.
The Periodic Table is called "periodic" because it is laid out to demonstrate the recurring ("periodic") chemical properties of the elements. They are listed in order of increasing atomic number; that is, the number of protons in the atomic nucleus.
Each row is arranged so that elements with similar properties fall into the same vertical columns. According to quantum mechanical theories of electron configuration within atoms, each horizontal row ("period") in the table corresponds to the filling of a quantum shell of electrons (remember the layers in the onion skin?).
In printed tables, each element is usually listed with its element symbol and atomic number and to date, there are 117 chemical elements whose discoveries have been confirmed.
Now that we have the nuclear physics out of the way, let’s look at these essential minerals in terms of essential nutrients.
The thing about minerals is that no matter how small they are, they're still rocks. Ever heard of "colloidal minerals"? That's a neat sounding phrase for "rocks" in solution; if you make it thick enough, some might call it mud.
The human body doesn't absorb rocks very well so it is preferable to get our minerals in food, and vitamins too, for that matter. It is best to get them in their natural state from plants (with a few exceptions).
In the case of supplements, plant sourced natural vitamins and minerals are absorbed best. Synthetics are unnatural; plant sourced nutrients are natural. Actually the science of mineral absorption goes quite deep. So if we are supposed to get our minerals in food, why supplement...
Why would a mineral be missing in our food? The content of minerals in food depends on the mineral content of the soil on which the plant grew and an adequate supply of water for those plants.
Plant absorption of minerals is greatly affected by water. Animals graze on plants or are given plant feedstock and the mineral content in beef, poultry, pork, or dairy products depends on the mineral content of their food.
Both vitamin and mineral content of foods can be degraded through long transportation times, processing with heat or chemicals, early harvesting, depleted soil, drought or inadequate irrigation and handling.
Considering absorption, our bodies don't automatically absorb everything we swallow. There are several synergistic relationships to be aware of.
Many minerals only get absorbed if other minerals or vitamins are present. On the other hand the presence of some nutrients may retard the absorption of dietary minerals in our body. Where appropriate, these special situations will be presented.
The term "mineral" is obsolete and misleading since what the body is looking for, is an ion of the mineral. Minerals in food are absorbed in their ionic form.
An ion is an atom that has gained or lost one or more of its orbiting electrons thus giving it a positive or negative electrical charge. The charge is what aids absorption of minerals.
The literature refers to minerals in food as being "anions" or "cations" and both refer to the charge. An anion has more electrons and thus has a negative charge; a cation has fewer electrons and is thus positively charged. So far, so good.
There are 12 essential minerals that we know the body needs to stay alive and functional. There is another 7 that we think are important to human life but the proof has not been firmly established.
As with vitamins, minerals have very specific and well defined multiple roles to play in the workings of our body. Just from TV commercials, we should all be somewhat familiar with calcium or at least its effects if we don't get enough.
Minerals in food that are used by the human body for nutrition can be classified into three groups.
The first is six minerals that are stored in large quantities in the body. They are Sodium (Na) and Chloride (Cl), Potassium (K), Calcium (Ca), Magnesium (Mg) and Phosphorus (P).
The second group is seven minerals in food that appear in trace amounts but whose importance has been well established. They are Iron (Fe), Zinc (Zn), Copper (Cu), Iodine (I), Floride (F), Selenium (Se) and Chromium (Cr).
The third group are minerals in food, also in trace amounts, that have been proven to be important in lab animals but whose role in human nutrition and health has not be firmly proven. They include Cobalt (Co), Molybdenum (Mo), Manganese (Mn) and Nickel (Ni) plus a few others.
The nutritional use and source of these minerals in food are briefly discussed below according to their group classification.
There are 17 recognized essential minerals however there are several more minerals in food that may be important or may even be harmful as toxins, cadmium and mercury for example. Only the 17 essential minerals are itemized below.
It is also required for maintaining the integrity of the cell's membrane and keeping junctions between cells intact which is critical for absorption. These are all highly important functions and thus serum levels of calcium are precisely controlled. If external sources of calcium are not available, the body will requisition calcium from the bones.
Natural food sources include dark leafy greens, broccoli, dairy products and yogurt (no surprise), oranges and asparagus. Absorption is the key to efficient utilization of calcium and requires vitamin D and a parathyroid hormone to ensure good absorption. Calcium is one of the most important of all minerals in food but it is important to know that it is absorbed better in some foods than others. Calcium in milk and diary products are easily absorbed but not so much in the green vegetables.
In relation to bones, about 50% of our body's magnesium is stored in our bones with the rest residing in the cells of tissue and organs. Magnesium and Calcium work together as partners in that Mg enhances the absorption of Ca in the intestine. This wonderful mineral has also been used to treat or prevent cardiovascular disease, diabetes and hypertension.
Another use for magnesium is in the mitigation of migraine headaches. For a very detailed discussion of Mg and migraines, go to http://www.help-for-migraines.com/magnesium-migraine.html.
In general, green vegetables (those containing chlorophyll) will contain magnesium; for example just a half cup of cooked spinach contains 66mg of Mg. Wheatgrass is getting a lot of attention lately (see link above) in that it contains more than 90 minerals, including high concentrations of the most alkaline minerals such as potassium, calcium, magnesium, and sodium. If you are a "juicer" consider adding a teaspoon of wheatgrass powder to your concoction. Most people do not get enough Mg in their diets so supplementation is called for in many cases. If taken as a supplement, an upper limit of 350 mg/day has been established however, it is difficult, if not impossible, to get a magnesium overdose from food.
Copper is obtained from organ meats, shellfish, lamb, pork, tofu and nuts. Whole grain cereals, dairy products, lentils, mushrooms, dried beans, canned tomatoes, curry powder and chocolate are also great sources for copper.
The thyroid gland, kidneys, salivary and gastric glands all compete for free iodide. In fact the thyroid must trap about 60 ug of iodide per day to maintain thyroxine levels. Thyroxine is the major hormone excreted by the thyroid and function to increase the number and activity of mitochondria in cells by binding to the cells' DNA, increasing the basal metabolic rate.Thyroxine causes an increase in the rate of carbohydrate metabolism and a rise in the rate of protein synthesis and breakdown. Thus a deficiency of iodine can lead to major problems with our metabolism.
When it comes to minerals in food, the iodine content of food (and water) is related to the iodine content of the soil. The primary food source is seafood but most people get adequate intakes of iodine from using iodized salt.
It has received a lot of attention for the prevention of prostate cancer but the evidence shows that the apparent benefit is limited to men with low basal plasma selenium and/or those who smoke.An upper limit of 400 ug per day has been set to avoid the possibility of selenium toxicity.
The best sources are Brazil nuts and kidney although neither are common foods in most diets. Moderately good sources are fish, shellfish, organ meats and whole grains while fruits and vegetables are poor sources of selenium. Organic selenium minerals in food are absorbed best while inorganic is poorly absorbed. If supplementing with selenium, be sure to use a brand that is plant sourced.
Before leaving the introductory page to minerals in food, it would be good to show what the government recommends as a Dietary Reference Intake (DRI) for some of the minerals listed above.
A DRI isn't just one number, it is a set of guidelines that includes Recommended Dietary Allowances (RDA), Adequate Intakes (AI) and Estimated Average Requirements (EAR); all segregated by age group, sex and lactation/pregnancy.
For our purposes, we will only give the RDA for some of the macro and trace minerals for male and female adults strictly to bring home how small the actual requirements really are.
Given the small amounts of dietary minerals we need, it becomes very easy to consume an excess of one or more minerals through supplementation.
An excess of particular minerals can create a host of collateral problems in absorption and bioavailability resulting in deficiencies and other issues that affect our homeostasis (balance in total bodily functions).
The important point is that an "RDA is the average daily dietary intake sufficient to meet the nutrient requirements of nearly all healthy individuals in a group". The key words here are "average" and "healthy".
The numbers will not apply to malnourished or sick people who will in all likelihood need to adjust their intakes depending on their medical condition with guidance from a qualified health provider.
Recommended Dietary Allowances for 31 - 50 Year Old Adults
Note that a mg is 1000th of a gram; a ug is one millionth of a gram. There are 28.4 grams in an ounce so with many of these elements we are seeing some very, very small amounts.
|Mineral||RDA Males||RDA Females|
That concludes our peek at the 17 essential minerals in food; and believe me, it was just a peek. The physiology of minerals in the body is extremely complex with vast implications for our health.
In general, it is imperative that we supplement our diets with natural, plant sourced vitamins and minerals...but even this statement is too simplistic.
For example, as was mentioned above, iron from red meat (animal sources) is heme-iron. Iron from vegetable sources is non-heme iron. The source of the iron greatly affects how well it is absorbed in the body.
Animal sourced iron is readily absorbed but not so with plant sources. As a general rule, plant sourced vitamins and minerals in food are superior for absorption but there are exceptions to every rule.
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