Metals and their respective levels of so-called toxicity seem to be a hot topic in the world of developmental disabilities.
What is a Metal?
Our body is composed of almost every natural elements found in nature. This is as true for metals as it is for water or carbon.
Let’s define metal before going any further: in astronomy, a “metal” is any element other than hydrogen or helium. Astronomers feel justified in grouping this diverse group of chemicals together because they only contribute 2% of the atomic matter in the universe. Seventy five per cent is hydrogen and the other twenty three per cent is helium. I like this definition because of its interesting perspective.
Minerals in the human body are elements required for several purposes such as the formation of blood, bones, teeth other tissues, osmoregulation of body fluids, control of physico-chemical processes, etc. Some of these minerals are needed in high amount i.e. more than 1 gram (Macro elements) and some of them are needed in low amount i.e. less than 1 gram (Micro elements).
These minerals are generally found in Milk, cereals, fresh vegetables and fruits, sea foods, fishes and meats. Their deficiency in the human body creates different types of problems and diseases. Their presence in excess can also cause different types of problems.
In this instalment we will review the roles of these minerals. We will go into more details in subsequent instalments.
- Calcium (Ca)
Structure of bone and teeth. Also plays a role in the growth of nerve cells.
- Phosphorous (Ph)
Structure of bone and teeth. Required for ATP, the energy carrier in animals.
- Magnesium (Mg)
Important in bone structure. Deficiency results in tetany (muscle spasms) and can lead to a calcium deficiency.
- Sodium (Na)
Major electrolyte of blood and extracellular fluid. Required for maintenance of pH and osmotic balance.
- Potassium (K)
Major electrolyte of blood and intracellular fluid. Required for maintenance of pH and osmotic balance.
- Chlorine (Cl)
Major electrolyte of blood and extracellular and intracellular fluid. Required for maintenance of pH and osmotic balance.
- Sulfur (S)
Element of the essential amino acids methionine and cysteine. Contained in the vitamins thiamin and biotin. As part of glutathione it is required for detoxification. Poor growth due to reduced protein synthesis and lower glutathione levels potentially increasing oxidative or xenobiotic damage are consequences of low sulfur and methionine and/or cysteine intake.
- Iron (Fe)
Contained in hemoglobin and myoglobin which are required for oxygen transport in the body. Part of the cytochrome p450 family of enzymes. Anemia is the primary consequence of iron deficiency. Excess iron levels can enlarge the liver, may provoke diabetes and cardiac falurer. The genetic disease hemochromatosis results from excess iron absorption. Similar symptoms can be produced through excessive transfusions required for the treatment of other diseases.
- Copper (Cu)
Contained in enzymes of the ferroxidase (ceruloplasmin?) system which regulates iron transport and facilitates release from storage. A structural element in the enzymes tyrosinase, cytochrome c oxidase, ascorbic acid oxidase, amine oxidases, and the antioxidant enzyme copper zinc superoxide dismutase. A copper deficiency can result in anemia from reduced ferroxidase function. Excess copper levels cause liver malfunction and are associated with genetic disorder Wilson’s Disease.
- Manganese (Mn)
Major component of the mitochondrial antioxidant enzyme manganese superoxide dismutase. A manganese deficiency can lead to improper bone formation and reproductive disorders. An excess of manganese can lead to poor iron absorption.
- Iodine (I)
Required for production of thyroxine which plays an important role in metabolic rate. Deficient or excessive iodine intake can cause goiter (an enlarged thyroid gland).
- Zinc (Zn)
Important for reproductive function due to its use in FSH (follicle stimulating hormone) and LH (leutinizing hormone). Required for DNA binding of zinc finger proteins which regulate a variety of activities. A component of the enzymes alcohol dehydrogenase, lactic dehydrogenase carbonic anhydrase, ribonuclease, DNA Polymerase and the antioxidant copper zinc superoxide dismutase. An excess of zinc may cause anemia or reduced bone formation.
- Selenium (Se)
Contained in the antioxidant enzyme glutathione peroxidase and heme oxidase. Deficiency results in oxidative membrane damage with different effects in different species. Human deficiency causes cardiomyopathy (heart damage) and is known as Keshan’s disease.
- Fluorine (Fl)
Fluorine is essential for the maintenance of solidity of our bones. Fluorine can also protect us from dental decay
- Cobalt (Co)
Contained in vitamin B12. An excess may cause cardiac failure.
- Molybdenum (Mo)
Contained in the enzyme xanthine oxidase. Required for the excretion of nitrogen in uric acid in birds. An excess can cause diarrhea and growth reduction.
- Chromium (Cr)
A cofactor in the regulation of sugar levels. Chromium deficiency may cause hyperglycemia (elevated blood sugar) and glucosuria (glucose in the urine).
The role of macro-elements in the human body
Lakatos B, Balla J, Vinkler P, Szentmihályi K.
Orv Hetil. 2006 May 21;147(20):925-30. Review. Hungarian.
The absorption of iron, calcium, phosphorus, magnesium, copper and zinc in the jejunum-ileum of control and iron-deficient rats.
Gómez-Ayala AE, Lisbona F, López-Aliaga I, Pallarés I, Barrionuevo M, Hartiti S, Rodríguez-Matas MC, Campos MS.
Lab Anim. 1998 Jan;32(1):72-9.
Ion regulation in the brain: implications for pathophysiology.
Neuroscientist. 2002 Jun;8(3):254-67. Review.
Macroelements, water, and electrolytes in sports nutrition
By Judy Anne Driskell, Ira Wolinsky
Published by CRC Press, 1999
ISBN 0849381967, 9780849381966