Demystifying Minerals: 02/2005

Minerals are fundamental to good health, from maintenance of healthy bones, tissues and cardiovascular well-being, to effective immune response.

References

Minerals are exogenously sourced micronutrients crucial to the smooth execution of innumerable functions within the human body. These essential atomic particles are integral to maintaining tissues, producing energy, synthesizing hormones and repairing cellular damage. Minerals also commonly partner with enzymes—intricate proteins produced by living cells—to catalyze biochemical reactions. In addition, minerals function in immunity, participating in nearly all components of the innate immune response to reduce propensity of infection.¹

Although the body is capable of synthesizing many essential compounds on its own, it is incapable of creating its own minerals, necessitating a steady supply of these nutrients through proper diet. In the United States, however, depleted foods and unhealthy lifestyles have produced widespread need for regular mineral supplementation among most groups of Americans.

“The typical American diet is full of processed foods, and processing leaches out the vitamins and minerals behind crucial physiological processes,” said Stacey Antine, director of corporate communications with Purchase, N.Y.-based Nutrition 21. “This is why mineral supplementation is essential to well-being.”

John Blanco, chief executive officer of Anmar International Ltd. in Bridgeport, Conn., agreed. “The importance of mineral supplementation is the same as that of supplementation in general,” he said. “In the case of many minerals, the normal diet will not contain the recommended daily allowance [RDA], making supplementation crucial.”

An inadequate supply of minerals leads to infirmity on numerous fronts. According to a study published in the journal Medical Hypotheses, mineral deficiencies beget a range of maladies including depression, allergies, low back pain, arthritis, poor digestion and cardiovascular disease.² The author of the study assessed nutritional status in test subjects via hair mineral analysis and a questionnaire regarding lifestyle, health status and diet. Those subjects found to have mineral deficiencies were consistently plagued by common chronic health conditions, particularly cardiovascular ailments. Unsurprisingly, the author of the study linked mineral deficiency amongst study participants to inadequate diet—consumption of nutrient-poor, highly-processed foods including white flour, refined sugar and harmful fats.

The issue of bioavailability is of particular relevance to mineral supplements. Numerous factors can affect mineral absorption, including overall health status, interaction with other nutrients, the presence of certain diseases and conditions, age and delivery method. Fortunately, mineral absorption can be increased in most individuals by learning how to take supplemental minerals; improving diet; obtaining adequate exercise, nutrition and rest; and reducing stress.

Within the body, iron’s functional forms include hemoglobin and enzymes, while its storage forms include transferrin, ferritin and hemosiderin. Signs of iron deficiency include extreme fatigue, pale skin, lightheadedness, brittle nails and headaches.

Iron has numerous physiological functions within the body. Its most crucial occupation involves oxygen transport by hemoglobin—the oxygen-carrying protein within red blood cells—whereby the four atoms of iron in the heme portion of hemoglobin serve to transport oxygen from the oxygen-rich lungs to areas of low oxygen concentration throughout the body. Iron is a component of proteins involved in processes including respiration, DNA synthesis and cell cycle regulation.³ Iron also functions in conversion of blood sugar into energy, and in the creation of new cells, hormones, amino acids and neurotransmitters. It is involved in the synthesis of collagen and elastin, and the amino acid carnitine, which assists in the metabolism of fatty acids. It is a component of enzymes involving liver detoxification and synthesis of neurotransmitters, and myoglobin, an iron-carrying protein in muscles that functions as an oxygen acceptor and an oxygen storage reservoir in muscle. It may play a role in maintaining healthy bone mineral density (BMD).⁴ Iron is also necessary for optimal immune response.⁵ During a pathogenic challenge, the body limits the accessibility of iron to harmful invaders, which can inhibit the growth of bacteria.

Although iron is involved in so many crucial processes within the body, total iron intake through diet and supplementation must be carefully regulated for optimal health. The mineral is potentially both toxic and therapeutic to the human body, and both iron deficiency and overload can lead to illness.⁶ For example, iron may positively impact certain diseases by preventing anemia—a risk factor for chronic heart failure,⁷ the development of ischemic disease⁸ and low-birthweight infants⁹—but encourage other diseases such as atherosclerosis¹⁰ by causing oxidative stress.

In the human intestinal tract, the absorption of heme-bound iron from foods is significantly more efficient than that of nonheme (ferrous) iron from most supplements. Approximately 25 percent of ingested heme iron is absorbed, while only 5 percent to 10 percent of inorganic iron is absorbed.

Studies have shown iron absorption can be improved by taking vitamin C (as ascorbic acid) at the same time.¹¹ Vitamin C increases iron absorption by holding it in the ferrous state.

Supplemental iron may cause nausea, vomiting and black stools, and may temporarily stain the teeth when delivered in liquid form; however, its most common side effect is constipation.

“Iron is sometimes highly constipating, so much so that I’ve had pregnant customers complain that ferrous sulfate, the form of iron recommended by their physicians has actually caused them to develop constipation and hemorrhoids,” said Neil Levin, CCN, DANLA, nutrition educator for Bloomingdale, Ill.-based NOW® Foods.

“You can imagine how this derails these women’s compliance with their supplement protocols. This ‘harsh’ form of iron is in many mass market and drug store multiple vitamins, prenatal formulas and iron supplements. But there is a nonconstipating form known as Iron Bisglycinate. NOW’s Iron Complex uses this gentle form of iron.” (NOW sources its chelated iron from Albion Advanced Nutrition, supplier of Ferrochel®.)

Within the body, calcium is the most abundant mineral, occurring primarily as hydroxyapatite—a calcium carbonate or calcium phosphate crystalline compound that lends strength and rigidity to tissues. Calcium is found mostly in human teeth, bones and, to a much lesser extent, blood.

Calcium plays key roles in processes such as blood clotting; the passage of fluids across cellular membranes; activation of various enzyme systems responsible for muscle contraction, fat digestion and protein metabolism; regulation of heartbeat; and regulation and transmission of nerve impulses. However, the mineral’s best-known purpose within the body is the development and maintenance of healthy bones and teeth. The Food and Drug Administration (FDA) permits a bone health claim for calcium-rich foods. Similarly, the National Institutes of Health (NIH) has approved a statement by its Consensus Development Process that asserts high calcium intake lowers the risk of osteoporosis.¹²

Although bones, in comparison to blood, contain the lion’s share of bodily calcium, the body strives to maintain serum calcium levels within sensitive limits. If calcium intake is inadequate, the body raids calcium from other sources to bridge the gap. Specifically, when blood calcium levels fall beneath unacceptable boundaries, low extracellular calcium signals the release of parathyroid hormone, which increases calcium absorption via three processes: the kidneys reduce calcium excretion, the intestines increase calcium absorption and the body pilfers calcium from bones.

Numerous clinical studies back the benefits of calcium. On the cardiac front, calcium supplementation has been shown to lower blood pressure in hypertensive patients.^{13,14,15,16,17} Dietary calcium reduces blood pressure by normalizing intracellular calcium and vitamin D levels, producing a hypotensive effect among patients comparable to that typically found in pharmacological trials of mild hypertension.¹⁸ In addition to lowering blood pressure, calcium may also benefit the cardiovascular system by reducing low density lipoprotein (LDL) or “bad” cholesterol levels.^{19, 20}

Numerous clinical trials have linked calcium to body fat reduction and weight loss. Higher intakes of calcium are associated with lower body mass index (BMI), waist circumference²¹ and adiposity.²² Further, dairy calcium intake has been linked with lower iliac skinfold thickness (a measure of body fat) and body weight by scientists at the University of Hawaii.²³

In the realm of bone health, calcium supplementation— particularly when combined with vitamin D—has been shown to increase BMD and help prevent osteoporosis.^24,25,26

Another clinical application of calcium is prevention of colorectal cancer.²⁷ Calcium supplementation in high-risk individuals has been shown to slow the rate of abnormal cell division in the colon promoted by high fat, phosphate and low fiber diets.²⁸

Finally, calcium supplementation may help control premenstrual syndrome (PMS), resulting in a major reduction in symptoms during the luteal phase.²⁹

The human body regulates calcium absorption via a biological control system dependent on fluctuating calcium levels. Bone resorption, intestinal absorption, renal tubular resorption, bone formation, and kidney and intestinal excretion affect calcium uptake. Calcium absorption is accomplished by an active transport system in the duodenum when calcium intake is low. When intake is high, the jejunum and ileum passively absorb the mineral.

The most common source of dietary calcium is dairy products. According to clinical trials, calcium from dairy products may arrest bone loss.³⁰ An unpublished, company-sponsored study investigated the bioavailability and biological activity of milk calcium (as LactoCalciumTM from Cyvex Nutrition) in vitro, and found the bioavailability of calcium from the product increased following simulated digestion, and treatment of bone cells with the digested calcium promoted the formation of mineralized bone nodules.

Although dairy has been shown to be an excellent source of readily absorbed calcium, milk has been increasingly displaced by other beverages in the diets of young people, according to Linda Douglas, Ph.D., R.D., scientific affairs manager for Golden, Colo.-based GTC Nutrition, which produces CalciLife™, a calcium and prebiotic fiber ingredient designed to enhance maximum calcium absorption. “This makes calcium supplementation or food fortification increasingly meaningful among the young, whose calcium requirements must be sufficient to support bone growth and development,” she said. “When bone is being built during phases of rapid growth, mineral supplementation can help bridge the gap between recommended intakes and the amounts actually being consumed.”

Certain nutrients taken with calcium serve to facilitate absorption. For example, calcium is often taken with vitamin D, which increases calcium absorption. Similarly, the human body cannot absorb calcium without magnesium, which is necessary for achieving bone density and growth. In the absence of magnesium, cellular calcium levels increase, preventing absorption by the bones and causing calcium buildup in inappropriate places. Buildup in the joints causes arthritis. If buildup occurs in the blood vessels, hardening of the arteries results. Accumulation of calcium in the heart leads to heart disease, while deposition of calcium in the brain leads to senility.

According to Levin, NOW Foods offers a “reverse ratio” supplement containing more magnesium than calcium. “This is helpful to those who eat a lot of dairy products or refined grains who may have some calcium added to their food but are not getting enough magnesium from vegetables and whole grains,” Levin said. “It is also useful to those who tend to get constipation or muscle cramps, as magnesium helps to relax muscles in opposition to calcium encouraging muscle contractions.”

While vitamin D and magnesium support calcium absorption, other nutrients negatively affect calcium uptake. For example, excess protein, sodium and phosphorus decrease calcium absorption by increasing urinary calcium excretion.

Magnesium acts as a cofactor in more than 300 enzymatic reactions in the human body and is necessary for key body functions including nerve impulse transmission, temperature regulation, detoxification reactions, muscular activity, energy production and the synthesis of DNA and RNA. It helps sodium and potassium move across cell membranes and plays a part in the metabolism of proteins, carbohydrates and fats.

Magnesium is also essential to bone formation and maintenance. Magnesium deficiency is frequently found in patients with osteoporosis³¹ and has been shown to cause bone loss in animals due to increased bone resorption and insufficient bone formation.^32,33

Like calcium, magnesium is another mineral known to confer cardiovascular benefits. It inhibits platelet aggregation, thins the blood, blocks calcium uptake, relaxes blood vessels and moderately lowers blood pressure. It has been shown to reduce the risk of coronary heart disease³⁴ and relieve symptoms in roughly 85 percent of mitral valve prolapse patients.^35,36 Magnesium also increases heart muscle oxygenation by improving cardiac contractility and the rate of survival following a heart attack. When administered intravenously during the early stages of a heart attack, the mineral causes a 70- percent decrease in deaths within one month following the episode.

Magnesium’s benefits extend beyond the cardiovascular and skeletal systems. The mineral can relieve muscle cramps,³⁷ particularly during pregnancy.³⁸ It can also benefit migraine patients, who have been found to have low magnesium levels in the brain,³⁹ by reducing the frequency of migraine headaches.⁴⁰ Finally, magnesium can help alleviate PMS symptoms. In a double blind, randomized clinical trial conducted at the University of Pavia, Italy, magnesium supplementation significantly improved mood plus women’s overall scores on the Menstrual Distress Questionnaire.⁴¹

According to recent U.S. Department of Agriculture (USDA) surveys, the average intake of magnesium by women 19 to 50 years of age is about 74 percent of the RDA, and about 50 percent of women had intakes below 70 percent of their RDA; meanwhile, men 19 to 50 years of age get about 94 percent of the recommended amount.⁴² Sub-optimal magnesium intake compromises cellular activity, especially in tissues of the heart, kidneys and nerves, and leads to higher risk for osteoporosis, clumsiness, cramping, heart palpitations, irregular heartbeat, low blood sugar, muscle spasms, nervousness and weakness.

Phosphorus inhibits magnesium absorption. Dietary phosphorus binds to magnesium, preventing absorption. Therefore, high-phosphorus diets, common among individuals who consume many meat dishes and soft drinks, may result in magnesium depletion.

First discovered as an essential trace element in 1955, chromium is present in healthy human bodies in amounts of only several milligrams. Chromium is involved in insulin function, regulation of blood sugar and activation of various enzymes for energy production. Since the 1950s, the mineral has been thought essential to normal glucose metabolism.⁴³ Chromium is biologically active only in a trivalent state formed with organic compounds. The most important of these is glucose tolerance factor (GTF), comprised of trivalent chromium, niacin, glycine, glutamic acid and cysteine. GTF enhances the blood sugar lowering effects of insulin by facilitating absorption of glucose by cells, thereby reducing the amount of insulin needed to control blood sugar levels. GTF has also been shown to lower elevated serum cholesterol and triglycerides.

Chromium is indicated for various other cardiovascular problems. Patients with coronary artery disease (CAD) have increased chromium requirements as their serum chromium levels tend to be lower than CADfree individuals. Chromium protects the myocardium⁴⁴ and has been observed to cause beneficial changes in serum lipids^45,46,47 by lowering blood levels of LDL and total cholesterol while raising HDL levels.^48,49

Chromium may also be of benefit to Type I and Type II diabetics, possibly due to the mineral’s positive effects on the regulation of insulin action and on carbohydrate, protein and lipid metabolism.^50,51 Studies show Type II diabetes patients have lower blood levels of chromium than those without the disease. Low levels of chromium perpetuate insulin resistance. In Type II diabetics, chromium as chromium picolinate, specifically, has been shown to reduce insulin resistance and to help reduce the risk of cardiovascular disease.⁵² Clinical research also supports the case for chromium supplementation in Type II diabetics to lower fasting blood glucose levels;^53,54 to lower plasma total cholesterol; and to have beneficial effects on HbA1c, glucose, insulin and cholesterol variables.⁵⁵ Chromium supplementation has also been shown to improve symptoms in diabetics with hypoglycemia.^56,57

Dietary chromium is assimilated in the small intestine through an inefficient active transport process. Since chromium levels decrease with age, supplemental chromium dosages should increase as an individual grows older. Common delivery forms for chromium include salts such as chromium polynicotinate, chromium picolinate and chromium chloride.

Selenium serves defensive roles within the body. Deficiency of the mineral leads to impaired immunity through reduced production of antibodies and weakened bactericidal activity, promoting diseases such as heart disease, diabetes and diseases of the liver.⁵⁸

As a powerful antioxidant, selenium may ward off cancer by reducing lipid peroxidation and neutralizing destructive hydrogen peroxide radicals.⁵⁹ The mineral is associated with lower incidence of cancers of the large intestine,⁶⁰ rectum,⁶¹ prostate,⁶² breast, gut,⁶³ ovary,^64,65 lung,⁶⁶ and bladder,⁶⁷ as well as lowered total cancer mortality⁶⁸ and total cancer incidence.^69,70

Selenium deficiency has been identified as a risk factor for cardiovascular disease. An inverse association between the incidence of ischemic heart disease and selenium intake has been described in numerous clinical studies.^71,72

Selenium is crucial to proper glutathione peroxidase activity in the eyes. Insufficient levels of the mineral in aqueous humor and serum of patients with senile cataracts may reflect inadequate antioxidant defense, which can result in the formation of cataracts.⁷³

In HIV patients, selenium may improve certain symptoms of the disease, according to Italian researchers.⁷⁴ However, their data failed to demonstrate a link between selenium supplementation and improvement in test subjects’ immunological and hematological parameters.

Both inorganic selenium salts and organic selenium compounds seem to be easily absorbed in the small intestine, but the mechanism of how selenium is absorbed is still under investigation. Severe gastrointestinal disorders such as Crohn’s disease may decrease the absorption of selenium, resulting in selenium depletion or deficiency.

Within humans, the highest concentrations of zinc are found in the liver, kidneys, bone, pancreas and muscles; and the mineral works with 300 different enzymes to facilitate a large number of physiological processes.

Zinc acts as an antioxidant⁷⁵ by scavenging free radicals and inhibiting cellular damage such as lipid peroxidation and DNA fragmentation, both in vitro⁷⁶ and in vivo.⁷⁷ In its role as a cofactor for the antioxidant enzyme Zn/Cu superoxide dismutase, the mineral helps regulate a wide variety of immune system activities, some of which involve T lymphocytes, CD4, natural killer cells and interleukin-2. Research has shown low serum levels of zinc invite oxidative stress through creation of a state of low resistance to chemically induced liver oxidant injury and by increasing the vulnerability of lipoproteins to oxidation.⁷⁸

Since zinc acts as an antioxidant within the body, it is involved in healthy immune function. According to clinical data, the mineral bolsters immunity by encouraging the proliferation of lymphocytes and the response of phagocytes. Zinc deficiency impairs overall immune function and resistance to infection,⁷⁹ antibodymediated responses to T cell-dependent and T cell-independent antigens, natural killer cell activity and delayed-type hypersensitivity (DTH) reactions.⁸⁰

Beyond its role in immune function, zinc is involved in numerous other activities within the body. It is a component of insulin and a regulator of insulin activity. It is also involved in sensory perception, including discernment of salt taste, dark adaptation and night vision. Zinc controls the release of stored vitamin A from the liver, and plays roles in the maturation of sperm, ovulation and fertilization. The mineral promotes skin health by facilitating wound healing, as in burns, surgical and other types of scars.^81,82 Zinc may reduce inflammation—a boon to arthritis patients.⁸³ In addition, zinc has been linked to prevention and treatment of the common cold. Zinc as gluconate lozenges^84,85 and nasal gel⁸⁶ substantially diminishes common cold symptoms including cough, headache, hoarseness, congestion, nasal drainage and sore throat, and reduce the duration of the illness.

Absorption of zinc occurs in the intestinal lumen and depends on the secretion of a zinc-binding factor produced by the pancreas. Diuretics, oral contraceptives, alcohol, coffee and tetracycline (when taken within two hours of a zinc supplement) can impede the absorption of zinc. Wheat products may decrease the absorption of zinc due to their phytic acid content. Dairy products are also thought to decrease zinc absorption, although they contain the mineral.

As with other minerals, various delivery forms of zinc are absorbed differently by different individuals. Zinc monomethionine, a new form of supplemental zinc available as OptiZincTM from Benecia, Calif.-based InterHealth Nutraceuticals Inc., has been shown in clinical trials to have enhanced bioavailability compared to certain other zinc delivery forms.^87,88

Although mineral supplements are bestsellers, they are not necessarily simple items to retail. From staying current on the latest research and comprehending the science behind mineral bioavailability, to helping customers choose delivery methods and providing accurate guidelines for maximizing absorption, the caring retailer in search of repeat business may find retail in this category a daunting task, at best.

With so many delivery forms on the market, and schools of thought on which may be best, the retailer might best serve his or her customers by learning the positives and negatives of every form he or she puts on the shelves.

Without extensive education, the retailer might find it difficult to advise patients on mineral supplementation regimes. Since so many factors affect mineral bioavailability, and the science behind mineral absorption is beyond most customers, the best solution may be to form partnerships with nutrition experts such as naturopaths or nutritionsts, who possess the knowledge to create personalized mineral supplementation plans, according to Chris Meletis, a naturopathic physician and educational consultant with Ogden, Utahbased Trace Minerals Research.

Levin added the need to consult an experienced practitioner applies in particular to customers looking to take individual minerals rather than multimineral supplements. “Mineral complex formulas are normally balanced for typical needs,” he said. “Taking imbalances of individual minerals may cause problems in some individuals. For example, there is a rough ideal ratio of zinc to copper for optimal health, so those supplementing large doses of one may create an apparent functional deficiency of the other.”

Ram Chaudhari, Ph.D., senior executive vice president and chief scientific officer with Schenectady, N.Y.- based Fortitech, noted product formulators represent another trusted source of expert guidance on mineral supplementation. “Mineral supplementation is about choosing the right kind of ingredients, in the proportions correct to deliver those nutrients, with an eye towards possible interactions,” he said. “Retailers and consumers might consider looking to highly experienced, expert formulators to handle the science behind mineral formulation and for supplementation guidelines.”

On the subject of mineral supplement marketing strategies, Henry Kriegel, president of Kriegel Marketing Group and spokesperson for Vancouver, British Columbia-based Sierra Mountain Minerals, gave the following advice: “Use point-of-purchase, end-aisle and counter displays; window banners; and DVDs (provided by manufacturers); and place products in condition-specific categories. Also, use thirdparty literature—particularly scientific studies using proprietary products—to help promote the sale of products. Many manufacturers rely on ‘borrowed science’ rather than original science to back up their products. For most, it is too costly and time-consuming. Yet, consumers are more sophisticated and, to generate trust, it is essential to provide them with the best literature as well as customer service.”

According to John McCarley, director of marketing with Morningstar Minerals, another solid strategy for mineral retailing is to conduct in-store testing for dehydration, since dehydration indicates mineral deficiency. “There’s a direct correlation between hydration and minerals,” said McCarley. “We recommend equipment designed to test for dehydration within approximately one minute. Roughly 90 percent of the people we’ve tested are dehydrated and in need of minerals.”

Like vitamins, minerals are a fundamental, widely used category of supplements. In spite of their pervasive use, however, few individuals possess the knowledge to use them effectively. The key to successful retailing of minerals is retailer and consumer education, and a willingness on retailers’ parts to refer their customers to experts for accurate, up-to-date guidelines. “Retailers must know how minerals function and how to recommend the better formulas,” said Levin. “This will ensure that customers use products that absorb better and contribute to their overall health.”

February 2005 Health Supplement Retailer
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