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NICKEL Nickel (Ni) is an essential nutrient for higher animals. Although a number of cellular effects of nickel have been documented, a deficiency disease has not been described in man. Nickel is found in highest concentrations in lung, kidney and some hormone-producing tissues. Although nickel-specific enzymes have yet to be identified in higher
animals, nickel can activate or inhibit a number of enzymes that usually
contain other elements. The production or action of some hormones (prolactin,
adrenaline, noradrenaline, aldosterone) responds to changes in nickel
concentration. Within cells, nickel alters membrane properties and influences
oxidation/reduction systems. Nickel has great affinity for cellular
structures such as chromosomes and ion channels, but its influence on
them at normal tissue concentrations is not known.
Deficiencies: It is difficult to induce a deficiency because
the requirement is low and nickel comes from a variety of sources. Feeding
a low nickel diet has reduced the growth of several species of animals.
At the cellular level structures become disorganized and membrane properties
change. Nickel deficiency has been linked to low blood glucose levels,
abnormal bone growth, poor absorption of ferric iron, and altered metabolism
of calcium, vitamin B-12 and energy nutrients. Diet recommendations: Based on animal experiments, the human
requirement for nickel probably does not exceed 100 µg/day. Nickel content
of Western self-selected and institutional diets ranges from 60 to 260
µg/day. Adequacy of the lower intakes may depend on the bio availability
of nickel (the nickel compounds ingested and foods consumed with them).
Food sources: Rich food sources of nickel include oatmeal,
dried beans and peas, nuts, and chocolate. The apparent absorption from
test meals is about 1%. Up to 27% is absorbed from water but the daily
intake of water provides only 1-2 µg Ni. Absorption is influenced by
the amount fed, the acidity of the gut, and the presence of various
binding agents (as phytate) or competing substances. In particular,
the levels of other minerals such as iron, magnesium, zinc and calcium
may alter nickel absorption from the gut. Toxicity: Toxicity has occurred in workers exposed to nickel
dust or nickel carbonyl formed in refining. Increased risk of nasal
and lung cancers was linked to occupational nickel exposure before current
workplace safety standards were set. Environmental sources of lower
levels of nickel include tobacco, dental or orthopedic implants, stainless
steel kitchen utensils and inexpensive jewelry. Repeated exposures may
lead to asthma and Contact dermatitis, symptoms of which may worsen
if the diet is high in nickel. The oral toxic dose is about 1000 times
the amount consumed in food. Different chemical forms vary widely in
toxicity. Excessive nickel in tissues is pro-oxidant (damaging chromosomes
and other cell components) and alters hormone and enzyme activities,
movement of ions through membranes, and immune function. These effects
can change glucose tolerance, blood pressure, response to stress, growth
rate, bone development and resistance to infection. Under some conditions,
large amounts of nickel may precipitate magnesium deficiency or cause
accumulation of iron or zinc. Recent research: Additional information is needed to establish
more precisely an intake/exposure range that is both adequate and safe,
and to account for other factors that affect the need and tolerance
for nickel. For further information: Kenney, M.A., & McCoy, H. (1992) A review of bio interactions of Ni and Mg. I. Enzyme, endocrine, transport, and skeletal systems. Magnes. Res. 5: 215-222 Nielsen, F.H. (1991) Nutritional requirements for boron, silicon, vanadium, nickel, and arsenic: current knowledge and speculation. FASEB J. 5: 2661-2667 Sigel, H. & Sigel, A., eds. (1988) Metal Ions in Biological Systems,
vol. 23. Nickel and Its Role in Biology. Marcel Dekker, New York, NY.
Statements on this website have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure or prevent any disease. Please Contact your physician. What Is The Use And Function Of Niacin What Is The Use And Function Of Pantothenic Acid
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