To Know Or Not To Know …
The ultratrace elements are present in extremely small amounts (less than 0.0001% by weight) in biological tissues. They include boron (B), bromine (Br), cadmium (Cd), fluorine (F), lead (Pb), lithium (L), nickel (Ni), silicon (Si), tin (Sn), and vanadium (V).
No deficiency syndrome has been described in humans. Small amounts of boron occur widely in the diet. Boron occurs in all foods produced from plants. Since 1989 its nutritional value has been argued. It is thought that boron may play some minor biochemical roles in animals, including humans. Supplemental boron may reduce excretion of calcium, estrogen and vitamin D and may thereby suppress osteoporosis (1).
Bromine has no known essential role in human or mammalian health, but inorganic bromine and organobromine compounds do occur naturally. Some organobromine compounds may be of use to higher organisms in dealing with certain parasites and bacteria. Marine organisms are the main source of organobromine compounds.
Elemental bromine is toxic and causes burns. Bromine gas is pale brown, smells like bleach and is very irritating to mucous membranes. Upon exposure, one should move to fresh air immediately. If symptoms of bromine poisoning arise, medical attention is needed (2).
Cadmium has no known useful role in higher organisms, but a cadmium-
For humans cadmium is mainly an environmental hazard, as it can irritate the lungs and accumulate in the kidneys. Environmental cadmium is mainly the result of fossil fuel combustion. It is also a byproduct in various industrial processes.
Bread, root crops, and vegetables also contribute to the cadmium exposure in modern populations.
However, tobacco smoking is the most important single source of cadmium exposure
in the general population. On average, smokers have 4–5 times higher blood cadmium
concentrations and 2–3 times higher kidney cadmium concentrations than non-
Cadmium exposure is a risk factor associated with early atherosclerosis and hypertension, which can both lead to cardiovascular disease.
Due to the adverse effects on the environment and human health, the supply and use of cadmium is restricted in Europe under the REACH Regulation (3).
Even if fluoride is not essential for humans, small amounts of fluoride may be beneficial for bone strength. Fluoride ions in contact with teeth is thought to limit cavities by turning the forming of hydroxyapatite of teeth into less soluble fluorapatite. This process works only by direct contact (topical treatment). Fluoride ions that are swallowed do not benefit the teeth.
Addition of flouride to public water supplies (water fluoridation) is used for about
Lead has no known biological function in humans. On the contrary lead is highly poisonous,
affecting many functions in the body, especially in the central nervous system, the
cardiovascular system, kidneys, immune system, and bone marrow. It can give rise
to nephropathy, colic-
Most exposure occurs through ingestion or inhalation. Lead poisoning typically results
from ingestion of food or water contaminated with lead, but it may also occur after
accidental ingestion of contaminated soil, dust, or lead-
By the mid-
Acute lead poisoning is treated using disodium calcium edetate: the calcium chelate
of the disodium salt of ethylene-
Lithium has no known role in normal biology. Nevertheless, lithium has been demonstrated
to have a mood-
Upon ingestion, lithium becomes widely distributed in the central nervous system and interacts with a number of neurotransmitters and receptors, decreasing norepinephrine release and increasing serotonin synthesis.
Lithium toxicity may occur in persons taking excessive amounts. The manifestations include nausea, vomiting, diarrhea, confusion, polyuria, seizures and coma. Other toxic effects of lithium include tremor, muscle twitching, convulsions and renal failure. Lithium is also believed to permanently affect renal function, although this does not appear to be common (6).
Nickel plays important roles in the biology of microorganisms and plants. Whether nickel has a biological effect in humans is still unclear. Nickel is found in the body in highest concentrations in the nucleic acids, particularly RNA, and is thought to be somehow involved in protein structure or function. It may activate certain enzymes related to the breakdown or utilization of glucose. Nickel may aid in prolactin production, and thus be involved in human breast milk production.
Nickel from inhaled nickel carbonyl from cigarette smoke, car exhaust, and some industrial wastes is toxic and can cause symptoms such as headaches, nausea, vomiting, or vertigo. Inhaled nickel accumulates in the lungs and has been associated with increased rates of lung, nasal, and laryngeal cancers.
Nickel allergy can also cause local skin or systemic reactions. The nickel in jewelry and dental materials may be sources of allergy that can give rise to eczema. The amount of nickel allowed in products that come into contact with human skin is regulated by the European Union (7).
Although silicon is readily available in the form of silicates, very few organisms have a use for it. In plants silicon has been shown to improve cell wall strength and structural integrity. Its exact function in the biology of animals is still under discussion.
Silicon is known to be needed for synthesis of elastin and collagen. It promotes strength in the hair, skin, and nails and helps maintain the elasticity of the skin. Silicon is present in bone, blood vessels, cartilage, and tendons, helping to make them strong. Silicon is important to bone formation, as it is found in active areas of calcification.
If you want to get extra silicon, eat more whole grains and fresh vegetables or use herbs, such as horsetail, alfalfa or comfrey (8).
Tin has no known natural biological role in living organisms. It is not easily absorbed by animals and humans. The low toxicity is relevant to the widespread use of tin in dinnerware and canned food. Nausea, vomiting and diarrhea have been reported after ingesting canned food containing 200 mg/kg of tin. A study showed that 99.5% of the controlled food cans contain tin in an amount below that level.
Organotin compounds with various organic groups can be very toxic. They are used as powerful agents to destroy bacteria, fungi, mites and ticks (9).
Vanadium plays a very limited role in biology, and is more important in ocean environments than on land. Eating fish and using vegetable oils in the diet will usually supply sufficient vanadium.
Rats and chickens are known to require vanadium in very small amounts and deficiencies result in reduced growth and impaired reproduction. Vanadium may increase insulin sensitivity and thereby improve glucose control in people with type 2 diabetes.
All vanadium compounds should be considered toxic. However, vanadium compounds are poorly absorbed from the gastrointestinal tract reducing the risk of toxicity. Inhalation exposures to vanadium and vanadium compounds result primarily in adverse effects on the respiratory system (10).