ULTRA TRACE ELEMENTS

Any mineral element with established, estimated or suspected daily requirement <1 mg per day. As, B, F, Mn, Mo, Ni, Si

Nielsen FH 1993

Fluorine

No substantial evidence that it is essential. But it protects against pathological demineralisation of calcified tissue (e.g. teeth). ... LPI

Arsenic

Best known as a poison; arsenic was also used pharmacologically (arsenicals – against anorexia, syphilis, rheumatism, malaria, TB, diabetes, etc. etc.)
Nutritional deficiency in animals demonstrated 30 years ago.
Uptake of soluble As compounds is efficient; excretion (in urine) is rapid.
Metabolic function is unclear; may be involved in methylation reactions, gene regulation?

Toxicity is relatively low – less toxic than Se, for example. Mechanism for toxicity: As is close to P in the periodic table and substitutes for it in biochemical reactions.

Photo
Arsenic poisoning from Bangladesh TopNews

Boron

Formerly a common food preservative. Then shown to be harmful at 500 mg/day. The use as preservative was terminated in the 1950's.
Rapidly absorbed and excreted.
Since 1981, found to be essential for animals, but physiological role not certain; perhaps in cell membrane function or stability, trans-membrane signalling, Ca²⁺ transport.

Manganese

Constituent of several metalloenzymes:

• arginase
• pyruvate carboxylase
• glutamine synthetase
• Mn superoxide dismutase

Activates various enzymes (most of them also activated by Mg).
Toxicology: among the least toxic of trace elements.

... LPI

Molybdenum

Transition element that readily changes its oxidation state, acting as an electron transfer agent in redox reactions.
Molybdoenzymes catalyse hydroxylation of various substrates

• Aldehyde oxidase
• Xanthine oxidase/dehydrogenase
• Sulphite oxidase (in cysteine metabolism)

... LPI

Nickel

Function not clearly defined for humans, but Ni-enzymes are known in lower organisms. May be involved in vitamin B₁₂ / folate metabolism.

Silicon

Involved in collagen formation and cartilage calcification.