By Lawrence Wilson, MD
© November 2014, The Center For Development
Calcium is the most plentiful element in the body, with most in the bones, teeth and nerves. Sadly, most people do not ingest nearly enough bioavailable calcium because when dairy products are pasteurized and homogenized, the calcium they contain is made less available to the body. Also, few other foods contain much calcium today.
Calcium is the primary structural mineral in the body, meaning it allows us to stand upright by giving strength to our bones. However, it has many other functions as well.
THE FUNCTIONS OF CALCIUM IN THE BODY
Calcium helps regulate cell permeability, is critical for maintenance of acid-base balance and assists many other body activities as well. These include male and female hormone secretion, cell division and osmotic balance. It stabilizes cell membranes, helps muscles relax and slows nerve transmission and the heart rate. Calcium also helps prevent fluid loss from cells and from the blood.
Calcium inhibits thyroid-releasing hormone and increases insulin secretion. It inhibits the sympathetic nervous system. It is required for phosphorus metabolism and energy production in the krebs cycle.
Calcium is also important as a detoxifier, preventing the uptake of lead and cadmium. Blood clotting and fat digestion depend on calcium. Calcium is extremely alkaline-forming and helps maintain the pH balance of the blood.
Stability, hardness and physicality are qualities of calcium. When deficient, one becomes weak and fragile. When calcium is in excess one becomes rigid and immobile. Its opposite elements are phosphorus and sodium, elements that activate and dissolve things. Calcium personality types are earthy, plodding, steady and blunt. They often move slowly and awkwardly and are unpolished in their language and mannerisms. They develop slowly and have a great potential for love and spirituality.
SYMPTOMS OF CALCIUM IMBALANCE
Deficiency Symptoms. These may include osteoporosis, rickets, non-union of fractures, tooth decay and insomnia. Teeth, fingers and other bones may be misshapen. Posture can be poor and legs bowed. Other symptoms are muscle cramps, irritability, hyperkinesis, hyperacidity, bruising, high blood pressure, fight-or-flight reactions, fast oxidation, lead and cadmium toxicity, tetany and cancer.
Toxicity Symptoms. Calcium toxicity symptoms may include fatigue, depression, defensiveness, muscle weakness, pain, arteriosclerosis, arthritis, kidney stones and gallstones. Others are bone spurs, rigidity, slow metabolism, constipation, social withdrawal and spondylitis (rigidity and inflammation of the spine).
Biounavailable Calcium. In many instances, calcium is biounavailable. This means it is present, but cannot be used properly. This condition causes symptoms of deficiency and excess at the same time.
CALCIUM IN THE LIFE CYCLE
Children and breast milk. Babies’ bones are flexible, as is their personality. Children’s growing bodies need loads of calcium for their bones and even more so for their nervous systems. This is why substituting soda pop, teas, water or even other milks such as soy milk for the more nutritious breast milk is a terrible crime against the growing baby.
Mother’s milk is a rich source of calcium and vitamin D that help create a calcified skeleton. It is, without question, the perfect food for babies, which is why it should be given for at least three years. Yes, three, not one or six months. Keep breastfeeding until the child will not accept any more, or about age three. This will give a child the best start in life. This is so critical that it deserves a separate article all about the many reasons for the benefits of mother’s milk.
It is unfortunate when, for various reasons, a child cannot receive breast milk. It would be wonderful if mother’s could help each other, as the milk does not have to come from the biological mother. Any wet nurse would do, and this used to be the habit and still is, among primitive tribes who understand more about the body than most modern women do.
Cow’s milk and milk substitutes. Pasteurized and homogenized milk is not as good a source of calcium. In earlier times, well-informed doctors recommended only raw, certified milk for children. This is milk from cows that have been rigorously inspected for disease by government authorities and must meet very high standards of cleanliness. It is an excellent product, although today all cows are hybrids and this is another issue that is discussed in separate articles. This excellent food is outlawed in most states, often not only for false health reasons, as is claimed, but for political reasons as well. There are forces that do not want people to take control of their lives and their nutrition, though it is sad to say.
Pasteurization. This harmful method of sterilization unfortunately allows milk from sick cows to be sold on the open market. It also permits lax standards of cleanliness on a few huge dairy farms that supply large areas of America. In addition, cooking the milk renders its calcium less biologically available to the body. It also damages the protein in the milk to a degree that is surprising, making it much harder to digest.
Copper and pasteurization. Copper rollers are, or were often used in the pasteurization process. This can add excess copper to the milk products, which includes cheese, yogurt, butter, whey and other dairy products. Goat milk is less damaged by pasteurization, for which reason it is preferable, though goats are also hybridized to a large degree, today, which renders the milk less ideal than previously. We hope that strains or cows that are more natural and healthful will be maintained around the world. There are few at this time in the United States, even among the organic and local dairies. They just do not give enough milk and have become obsolete, so to speak.
Homogenization is another insult to milk. Vigorous shaking breaks up the fat particles so they stay in solution instead of rising to the top. However, the small particles are absorbed directly into the blood stream instead of being digested properly. This renders the milk less healthful.
Soda pop is worth mentioning because companies that produce it target children and young mother’s due to its “convenience” It is about the worst beverage for children, not to mention adults, and all children should be made to avoid this monster, if at all possible.
The fact that sodas are still sold in schools, along with fruit juices, should make parents remove the children from this environment. However, this level of awareness is a long way off. Children must have tremendous amounts of calcium to develop normally, and these two beverages tend to deplete calcium instead of supplying it.
Here are reasons to avoid soda and juices for children:
1) Little Calcium. Soda pop and juices supply little if any calcium, even if “enriched”, usually with a cheap form of supplemental calcium. Orange juice has some calcium, but even this product is not healthful for anyone, in our opinion.
2) Fruit or phosphoric acids. Sodas, in particular, and orange juice, too, are quite acidic foods. This means they contain fruit acids or phosphoric acid added to soda pop. These are hard to digest, no matter what the ‘health authorities’ say. Citrus like grapefruit is somewhat better because it has so little sugar, the other harmful ingredient in fruit juices and soda pop.
3) Sugars to saturation. Sugar is discussed in other articles. Simple carbohydrates are a very damaging food for children, unless combined as in natural milks, especially mother’s milk. They also upset calcium metabolism more than any other single factor in many instances. Melvin Page, DDS and others wrote extensively about this in his book, Degeneration, Regeneration, Nutritional Development, FL, 1949,1980. and in other works.
4) Too much liquid. This is another problem with drinking water, teas, soy milk in particular and other diluted beverages. That is, the nutrient density of these beverages is so low the baby must drink too much liquid to get any nutrition at all. This makes for upset stomachs and more problems for the kidneys and many other organs. It is a subtle problem with formula and all substitutes for mother’s milk in most cases.
4) Phosphoric acid and some fruit acids. Phosphoric acid, used in most soda drinks to provide a “kick”, powerfully binds to calcium in the intestinal tract, forming calcium phosphates. This prevents the bound calcium from being absorbed properly. Fruit acids, which include phosphoric, malic and others, can also do the same thing to a lesser degree, possibly. This is one reason that people eating a lot of fruit have decayed teeth. It is not just the surface effects of fruit acids on the dentine of the teeth. It is also the absorption and binding of calcium by fruit acids, rendering it less absorbable
This is not to be confused with the fact that absorption of calcium requires an acid medium in the stomach. This is the truth. However, the proper acid is hydrochloric acid. This enables calcium, if it is unbound, to be mixed with amino acids and thereby chelated. This word means to be bound to a mineral transporter, such as an amino acid or other molecule. This, in fact, permit greater calcium absorption. However, binding calcium with other materials, such as phosphorus, creates insoluble compounds that are poorly absorbed.
5) Low in essential fatty acids. One of the great benefits of most mother’s milk is the fatty acid content. This is absolutely essential for childhood development of the nervous system. A cause of autism, attention deficit-hyperactivity disorder and many more developmental delays and learning problems stem from inadequate fatty acids in the body. It is not easy to obtain the needed ones from modern food. Also, children fed exclusively formula are all deficient in fatty acids and other nutrients, some of which have not been discovered and will not be so for some years. This applies even when vitamins and other nutrients are added to the milk formula.
The body needs a wide range of fatty acids for its development. Fish oils can supply most of these. Today’s food is deficient in many of them, however, some of which are known and many are not known.
6) Unknown Needs. Thus, a hidden reason for using breast milk is to obtain all the nutrients we have not discovered as yet. Based on previous experience, there are plenty of these nutrients for babies, children and even adults.
7) Caffeine And Many Chemicals. These are common in almost all beverages except simple herb teas, which may be given to children in small quantities. Otherwise, however, one is feeding the child a chemical cocktail. Sugar substitutes are even worse that sugars in some cases, such as aspartame (Equal or Nutrasweet). The other non-caloric sweeteners are less harmful, but not too much in most cases. They upset the delicate taste detection methods in children, leading to other problems of metabolism, obesity among them.
8) More Toxins. This is a serious problem when some tap water is used with powdered or concentrated formula. People forget that tap water is not a healthful product, with its added chlorides, fluorides, aluminum (used in most every municipal water system), copper in some areas, and more.
Most urban water supplies have some degree of contamination with medical drugs, for example. Your baby gets a dose of antibiotics, sleeping pills and much, much more with each bottle it is fed, for this reason.
Most people also do not understand that the body excretes most of the drugs it is fed. Only a small percentage of the total dose remains for a few hours to have its intended effect on the body.
9) More toxins. Babies are also exposed to radiation poisoning through the water used in many nations. Other problems with using tap water are parasites, bacteria, viruses, toxic metals and more. The point is, avoid using formula if possible, and if necessary, use distilled or spring water only to dilute powdered formula. Otherwise, filter or at least boil water to make it a safer product.
Concluding remarks on breastfeeding. This should convince anyone of the value of breastfeeding. If a woman can manage it, breast feed directly to your child. If, however, you must be away from the child, the bonding with the child will not occur as well. However, breast milk can be pumped out and saved, using a breast pump. Refrigerate it if and only if it will be used more than an hour or two after it is pumped. It will have to be heated a little, or the child will usually vomit. Also, if the woman is very upset, using a breast pump may also be best.
A baby is very sensitive to the vibrations of the mother. If the mother cannot relax, pumping the milk and then handing it the child in a cradle may actually be better than holding a baby in an agitated state and believing the child can assimilate the milk properly. The child must be relaxed, as with adults, to feed properly. Children, however, will often vomit if they are uncomfortable, whereas adults usually will just develop bloating, gas and other problems by eating when upset, anxious, in a hurry or not chewing or resting while eating.
DIETARY SOURCES OF CALCIUM
Excellent calcium foods include raw milk, raw cheese and raw yogurt or kefir. The next best may be fresh or even store-bought carrot juice. Everyone should drink about 10-12 ounces of this daily for its calcium content. Children need proportionately less. Another excellent source is the bones of animals that are boiled, preferably, for a number of hours to separate the calcium from the bone. One then drinks the soup stock made of bones.
Other good sources are sardines, caviar, cod roe, and good quality egg yolks that are not overcooked. However, I do not suggest eating caviar or other fish eggs on a regular basis because they contain some toxic metals.
The next best sources are kelp, yeast and toasted almond butter. Other seeds such as sesame, sunflower and pumpkin are other decent sources if one eats enough. We do not recommend many seeds in the diet, however. Cooked or better juiced dark green vegetables such as kale, collard greens, mustard greens, turnip greens, comfrey and carrots are also good sources.
Corn tortillas or corn chips prepared in the traditional way with lime are other good sources. However, most corn chips do not contain lime and are not a good source of calcium. Neither is corn bread or corn eaten as a vegetable.
Strict vegetarians often develop a calcium deficiency. Although they eat greens, nuts and seeds, the calcium from these sources is less available than in eggs and raw dairy products. Their diets are also low in calcium synergists such as vitamins A and D.
The best calcium supplements, in my view, are carrot juice, bones such as found in some cans of sardines and salmon, bone broth and kelp. Some products made from raw dairy products may be goods sources as well, but this is variable. These sources, in theory, combine a very usable form of calcium with other vitamins and minerals needed for calcium utilization. Those with a hyperthyroid condition may have trouble with the iodine in kelp, in which case they should just reduce the amount used daily.
Non-food calcium supplements. Many good forms are sold. However, our experience is that most of them are not nearly as effective as the food forms of calcium supplements. I am not sure why this is so. Among those often sold are calcium citrate, calcium chelate, calcium lactate and calcium gluconate. Bone meal used to be popular and is an excellent supplement if it is not contaminated with lead. Microcrystalline hydroxyapatite crystals (MCHC) is another excellent form of calcium. Other forms that are less common are calcium orotate and aspartate.
Calcium carbonate, phosphate, dicalcium phosphate and tricalcium phosphate are not well absorbed as the phosphorus binds tightly to the calcium. Calcium carbonate is common chalk. It is extremely alkaline and found in Tums, other anti-acids and coral calcium. People who are too acidic may benefit from it. Unfortunately, stomach acid is important for digestion and reducing it too much interferes with digestion.
Coral calcium. In his book, Barefoot on Coral Calcium. An Elixir of Life?, author Robert Barefoot mentions that coral calcium contains significant amounts of iron, aluminum and strontium. Aluminum and strontium are poisons. Most people also have toxic levels of iron stored in their livers. Dr. Barefoot dismisses this problem. His book is poorly referenced and contains no scientific studies of coral calcium. I suggest avoiding coral calcium.
Toxic metals can make one feel good for a while. This is one reason people smoke cigarettes which supply lead, arsenic and cadmium. Problems develop ten years later or more.
Many commercial calcium preparations in drug stores also contain lots of sugar. Some are even sold like candies. These products will be less effective because sugar upsets calcium metabolism. Usually the calcium is in the form of calcium carbonate, a poorly absorbed form. I suggest avoiding calcium carbonate and sugared calcium supplements.
CALCIUM AND THE FIGHT-OR-FLIGHT RESPONSE
When our bodies come under a lot of stress, they move into what is called the fight-or-flight response. When this happens, the body excretes calcium in the urine. This causes the muscles and nervous system to go into a state of heightened alertness to respond to stress. Those who live in a fight-or-flight pattern much of the time are continuously losing calcium in their urine.
A different phenomenon occurs when a body is in slow oxidation, or the exhaustion stage of stress. In this common situation, calcium is lost into the tissues. Low tissue sodium and potassium levels prevent calcium from remaining in an ionized or soluble form in the blood. Instead, it precipitates and deposits in many body tissues including the joints, arteries, kidneys and elsewhere. This is a cardinal sign of aging.
The process is identical to calcium deposition on faucets in hard water areas. ‘Hard’ water does not contain enough sodium to ‘soften’ the calcium. Adding salt or potassium with a water softener prevents calcium deposition. The same approach can dissolve calcium deposits in the body. Eating salt and potassium are not adequate. One must restore adrenal glandular activity which is responsible for normal retention of sodium and potassium.
Magnesium helps keep calcium in solution. Sources are nuts, seeds, kelp, molasses and yeast. Silica is another calcium synergist. It may be transmuted into calcium according to Dr. Louis Kervan, author of Biological Transmutations. Chlorine, hydrochloric acid in the stomach and adequate protein in the diet are also required for calcium utilization.
Potassium. This is another potent calcium synergist, although in high quantity it can become an antagonist by dissolving calcium from the bones and elsewhere. See the section in this article and separate articles on fast oxidation for more on this topic. Potassium is absolutely critical for calcium metabolism in many enzymes. In fact, a recent study found that potassium is required for bone strength or density. (Jehle, S., et al., Partial neutralization of the acidogenic Western diet with potassium citrate increases bone mass in women with osteopenia, J Am SocNephrol. 2006;17:3212.)
Copper is required to fix calcium in the bones and helps raise the tissue calcium level. Many people have biologically unavailable copper which causes their calcium problems. In fast oxidizers, copper deficiency contributes to a calcium deficiency.
Iodine is required for thyroid activity. Low thyroid activity is associated with biounavailable calcium and calcium deposition in the soft tissues. The best sources of iodine are fish and sea vegetables like kelp or dulse. Iodized salt is not as good a source. Boron apparently improves adrenal gland activity, which makes copper more available. Boron is found in nuts, beans, leafy greens and bone extracts.
Vitamins A and D are important for calcium utilization and are commonly deficient. Vitamin D is only found in enriched milk, fish oils and from sun exposure. Vitamin A is only found in fish oils and meats. Beta carotene must be converted to vitamin A. Low thyroid activity impairs the conversion. I always recommend vitamin A, not beta carotene.
Adequate adrenal hormones levels are also essential for proper calcium metabolism. Hormone replacement therapy, however, is not the best or only way to improve hormone production. Usually, a nutritional balancing program will easily improve natural hormone production. Infrared light is also extremely beneficial for calcium metabolism.
Sugar upsets the calcium/phosphorus ratio in the blood more than any other single factor, according to researcher Dr. Melvin Page. It also stresses the adrenal glands and upsets the hormone balance which affects calcium metabolism.
Lead and cadmium antagonize and replace calcium in the bones and elsewhere. Hidden lead toxicity, for example, is an important cause of weak bones and osteoporosis. Tests for toxic metals may not reveal it when it is deeply embedded within the bones. A hair analysis may reveal it later as it comes out of the body through the hair and other routes.
Excessive fluoride replaces calcium in the bones, causing them to become brittle and weak. Sources are fluoridated tap water, some mineral waters, foods contaminated with fluorides from the soil and foods processed with fluoridated water like reconstituted fruit juices and soda pop. Some foods are naturally high in fluorides like tea. Drinking fluoridated water or consuming products processed with fluoridated water is a cause of osteoporosis.
Excess phosphorus binds calcium and impairs its absorption from the intestines. Sources are soda pop and diets very high in animal protein. Phytates found in high grain diets, soy and other beans bind calcium preventing its absorption. Excessive oxalic acid found in spinach, cranberries, rhubarb and tea can interfere with calcium utilization, but only if eaten in large quantities. Low stomach acid and low protein diets impair calcium utilization.
TESTING FOR CALCIUM IMBALANCE
Serum Calcium. Calcium tests in the blood are often of little value. The body robs the bones to keep the blood level in a narrow range. A bone density test is therefore the best, but it too has flaws discussed below. Also, in a healthy person, excess calcium is quickly moved from the blood into the tissues.
Urine tests are a little better, offering a way to measure how much calcium one is excreting. However, they are subject to daily variations due to stress, hormonal factors and others.
X-rays are helpful to assess bone density. However, osteoporotic changes are a very late indicator of calcium imbalance. Also, osteoporosis can be due to other imbalances besides calcium. The bones require boron, magnesium, manganese, zinc, copper, phosphorus and other nutrients in addition to calcium. Low bone density does not necessarily indicate a greater need for calcium. A normal bone density test does not necessarily mean one’s intake is sufficient.
Hair mineral analysis. Hair must not be washed at the laboratory for accurate hair calcium readings. I recommend Analytical Research Labs for this reason. Trace Elements, Inc. does not wash the hair, but they are not as careful, their graph is difficult to read, their products are not as good, and their corrective programs are terrible.
The level of calcium in the hair tissue can vary from about 7 or 8 mg% to over 1000 mg%.
If the hair analysis is interpreted properly, which is discussed in detail on this website and in the book, Nutritional Balancing And Hair Mineral Analysis, (2010 and 2014 editions), hair mineral testing is very helpful to evaluate many aspects of calcium metabolism in the body. Among these are the degree of biounavailable calcium, deficiency states, calcium loss into the tissues and others.
Interpretation of hair tests. Essentially, the tissues such as the hair become depleted long before blood tests or x-rays reveal a deficiency. However, one must understand that as calcium is depleted the reading in the hair may actually increase due to loss of calcium into the tissues. In the state called fast oxidation or an alarm stage of stress, generally the hair tissue calcium will be low, or at least low relative to sodium and potassium. This is due to excessive thyroid activity which lowers tissue calcium.
In the state called slow oxidation, often the hair calcium level will be very high due to calcium precipitation into the soft tissues of the body. In this case, calcium becomes biounavailable. That is, an excess occurs in the tissues but it is not available to the body. It becomes essentially a toxic mineral, causing calcium deposits in the joints, arteries, kidneys, brain and elsewhere. Much more on calcium interpretation is in other articles on this website.
ESOTERIC UNDERSTANDING OF CALCIUM
This section is more advanced. Calcium may be considered the life element. It is required for all life on earth for complex reasons. Its importance cannot be overemphasized for this reason.
Calcium is a compressive or pressure mineral. It exerts a kind of pressure that allows life to flourish on earth. Without it, life cannot exist. As one’s calcium stores are used up, life ebbs out of the body. As one replaces the body’s calcium properly, life energy returns. In this regard, calcium functions as a kind of valve or receiver of etheric energy that fuels the human, animal and even the plant frame or organism.
Calcium may be said to represent structure, meaning living structure, not just the bones and teeth. Calcium may also be said to represent voltage in an electrical analogy, which is more than an analogy.
In fact, calcium actually regulates the voltage at which nerve cells fire. Too much biounavailable calcium and too little available calcium will stabilize cell membranes too much and prevent the proper firing of the nerve cells. This is one of the problems in slow oxidizers, in particular. This causes mental and physical depression, among many other symptoms. It also impairs the passage of nutrients and waste products through the cell membranes, which is deadly if it continues for any length of time.
In contrast, too much available calcium, which occurs, at times, in some very fast oxidizers, causes excessive cell membrane permeability. This can cause problems such as too much thyroid hormone passing into the cells too quickly. This leads to a condition in which the serum thyroid hormones are low, yet a person really does not need more thyroid hormones. He or she really needs a lower degree of cell permeability. When doctors give thyroid hormone replacements in these cases, they can cause severe illness or even death by further unbalancing the body and causing an even faster oxidation rate. In this regard, the balance of calcium, and its bioavailability, is really a key to health in all living things.
CORRECTING CALCIUM IMBALANCES
Here are some important principles I use when addressing all calcium imbalances:
1. Never attempt to correct a calcium imbalance in isolation. This means that one must correct all the macrominerals or electrolytes, not just calcium. The reason is they are all closely tied together. Dr. Paul Eck realized this, but most doctors, even holistic doctors and naturopaths, do not understand how all the electrolytes are closely related.
2. Always begin by balancing the oxidation rate on a properly performed hair mineral analysis. This works because it balances the calcium and the other electrolytes at a deep cellular level. Any other type of balancing using blood tests, urine tests or others, so far, I have found to be far less safe, reliable or accurate. Some people use machines, kinesiological testing or other methods. None appear to be half as good as a properly performed and correctly interpreted hair mineral test when it comes to balancing and replacing calcium in the body.
3. The only valid method of interpreting a hair mineral analysis that I have come across is that devised by Dr. Paul C. Eck, founder of Analytical Research Laboratories in Phoenix, Arizona. I say this because many doctors have written books about hair analysis and how to use it. I have experimented with other methods of doing the test, such as washing the hair at the lab, and this does not work well at all. Only the method of Dr. Paul Eck, and none other, seems to offer the best results.
4. An important aspect of Dr. Eck’s method is periodic retesting of the hair and adjustment of the nutritional balancing program every 3 to 6 months or so. This is absolutely essential to complete the balancing of calcium in the body. This is because as time goes on, the biochemical balance in the body will shift. At times, these shifts are dramatic, while at other times they are less extreme. However, one must retest the hair and make a ‘mid-course correction’ every few months or the balancing and correction process will often stop. Patients need to understand this thoroughly, as many do not bother with retests and then wonder why their program does not work well.
5. In addition to Dr. Eck’s brilliant work, I have found that the diet, the lifestyle, the drinking water (both quantity and quality), and certain detoxification procedures such as near infrared sauna therapy and coffee enemas can greatly enhance all nutritional balancing programs. In some cases, these are absolutely essential or progress will be minimal.
Here are a few other points about calcium that I have observed in the American population, and in others, to a lesser degree.
1. Everyone needs more calcium today. This is apparently due to the pasteurization of milk, and the consumption of refined grains, refined sugar, and other nutritionally deficient foods by almost everyone. In addition, impaired digestion, intestinal infections and imbalances, and stress all tend to reduce calcium absorption, digestion and utilization today.
2. On nutritional balancing programs, everyone receives at least 750 mg of supplemental calcium chelate or citrate, along with about 450 mg of supplemental magnesium chelate or citrate. If a hair analysis indicates a severe imbalance such as a four lows pattern or perhaps others, the amounts need to be greater.
Synergistic nutrients are always needed, as well, to help with calcium absorption and utilization. These include a digestive aid, zinc, vitamin D3 5000 iu daily for adults, and perhaps copper and other nutrients depending upon the hair mineral test results.
OTHER ARTICLES ON THIS SITE RELATED TO CALCIUM
Jensen, B., The Chemistry of Man, 1983.
Kervan, L., Biological Transmutations, 1972, 1998.
Page, M., Degeneration-Regeneration, 1949,1980.
Pfeiffer, C., Mental and Elemental Nutrients, Keats Publishing, 1975.
Price, W., Nutrition and Physical Degeneration, 1949, 1979.
Schroeder, H., The Trace Elements and Man, Devin-Adair Company, 1973.
Wilson, L., Nutritional Balancing and Hair Mineral Analysis, 1998, 2005, 2010.