Minerals and Health

By Dr. Gordon Chang, Ph.D.

 

There are over 18 different minerals that are known to be essential for normal health.   These minerals are used as components for bone formation, regulation to the body’s electrolyte balance, proper functioning of enzymes, regulation of heart beats, proper functioning of the immune system etc.  Our daily diet should provide us with all these essential minerals.  Some of these minerals (e.g. Calcium, phosphorus, potassium, magnesium, sodium, sulphur and chlorine, iron) are needed in larger quantities and other minerals (e.g. manganese, selenium, zinc, copper, iodine, boron, molybdenum, silicon, chromium and vanadium) are only needed in lower amounts (trace amounts).  The body does not excrete a large amount of these minerals on a daily basis.  When the body is healthy, it has very finely tuned biochemical mechanisms to control the quantity of the major minerals.  However, there is a daily loss of these minerals that must be replaced from dietary sources.  If these minerals are not replaced many different symptoms are experienced due to deficiency.  When the deficiency is great we observe definite clinical signs, however, when the deficiency is low sub clinical symptoms (e.g. tiredness, low immunity) are seen.  The greater the deficiency the more pronounced the symptoms.  For example low calcium intake and absorption by the body can lead to osteoporosis.  I will now review a selected number of minerals below.

Calcium is one of the most important minerals in the body.  It is used in the formation of bone and teeth, the regulation of heartbeats, proper clotting of blood and contraction of muscles.  Calcium deficiency has been associated with muscle and leg cramps, osteoporosis and high blood pressure.  Calcium occurs naturally in many types of food (e.g. milk, kelp, tofu, nuts, and kale).  The best way to get calcium is from food sources.  However if you need to obtain calcium from a supplement the calcium should be in a soluble form for optimum absorption.  Several studies have shown that calcium available as calcium citrate is better absorbed than calcium obtained as calcium carbonate.  In addition calcium citrate has been observed to inhibit the formation of kidney stones.  The current RDA (recommended daily allowance) for calcium is 1000 mg in the adult male and 1200mg for pregnant and lactating women and children.

Magnesium is another mineral that is important for bone formation, for proper functioning of several key enzyme systems (approximately 300 known systems).  It has been estimated that in the general population magnesium is way below the RDA (350 mg for adult males and 280 mg for adult females).  Studies have indicated that magnesium supplementation has helped in the following conditions: asthma, high blood pressure, osteoporosis, kidney stones, premenstrual syndrome (PMS), and leg cramps.  The best food sources of magnesium are kelp, wheat bran, wheat germ, tofu, and nuts.

Supplemental magnesium is available in many different forms all of which seem to be well absorbed.  However, magnesium citrate is one of the forms that are best tolerated by the body.  Individuals suffering from kidney disease should consult their health care professional before taking magnesium supplements.

Zinc is known to be essential in over 200 known biochemical reactions.  It is important in many enzymatic reactions which are necessary for the proper functioning of the thyroid, the sex hormones, the immune system to name but a few.  The major food sources for zinc are fresh oysters, pumpkin seeds, nuts and ginger root.  The recommended daily allowance is 15mg for adult males.  In high doses (greater than 150mg per day for a prolonged period) zinc can depress the immune system and cause anaemia.  The best form of supplemental zinc is from zinc citrate.

Selenium is a very important mineral even though it is only required in trace amounts.  The major food sources of selenium are wheat germ, Brazil nuts, oats and barley.  Selenium has been shown to function as a cofactor in one of the body’s most important antioxidant system (glutathione peroxidase).  Studies have shown that when selenium is supplemented in the diet there is a reduced risk of cancer and the immune system is boosted.  There is no RDA for Selenium, however a daily intake of 50-200 micrograms (mcg) is often recommended.  Selenium at high doses, (e.g. 900 micrograms for a prolonged period), is known to produce many serious and toxic side effects.  Therefore, one should not exceed the recommended dose of selenium without the supervision of your health care provider.

Silicon has been shown to be important for the proper formation of ligaments and bone.  Recently low silicon has been associated with osteoporosis.  In fact increased dietary silicon has been shown to increase bone growth and bone density.  The major food sources of silicon are unrefined grains and root vegetables.  There is no RDA for silicon; however based on animal studies a daily intake of 20-40 mg is adequate and safe.  Silicon is generally regarded as being non-toxic.

Copper is important for (a) the formation of ligaments and tendons and connective tissue; (b) the absorption of iron from the gastrointestinal tract; (c) the activity of an important antioxidant enzyme (Superoxide dismutase).  The major food source of copper are nuts.  There is no RDA for copper but a safe and sufficient dose of copper for an adult is estimated to be from 1-3 milligram per day.  High doses of copper are known to interfere with the absorption of zinc.

                Manganese is important for a) blood sugar control, (b) Antioxidant activity via SOD (Superoxide dismutase) and c) bone growth and strong hair and nails. The major food sources of manganese are nuts.  There is no RDA for manganese but a dose of 3-5 mg per day is usually recommended as being safe.  Therapeutic doses (recommended by a health care professional) as high as 100 mg per day have been used without any ill effect.

The minerals that have been addressed have a greater tendency to be deficient in individuals in our society.  These deficiencies can arise from the lack of nutrients in our everyday foods.  Lastly, I cannot stress enough the importance for individuals to realize the significance of minerals for their general health and well-being.