Avoid all foods that are routinely high in nickel content such as cocoa, chocolate, soya beans, oatmeal, nuts, almonds and fresh and dried legumes. Avoid all drinks and vitamin supplements with nickel and canned food.

1. Name:- komal G. Goplani
Std:- sy. Msc. CND
Topic name :- trace elements ( nickel )
Submitted to :- Dr. Sudhakar Rao Sir.

2. TRACE ELEMENTS
Elements ingested in milligrams or less per day are
referred to as trace elements.
Trace elements enter the food chain from soil, water,
and atmospheric particles derived from weathered geo-
logic formations and volcanic eruptions. Two concepts
are important when considering the essentiality of a trace
element metals. First, evolving biologic systems were based
on geochemistry and aquatic chemistry, which used metals
and metalloids to perform catalytic,structural, and signaling
functions.

3. The second concept is chemical reactivity. In living
systems, reactive metal atoms are not “free,” but
rather are stabilized by coordinate bonds to functional
groups of amino acids in energetically
strained (entatic) catalytic sites of proteins or are
bound to ligands such as nucleotides and tetrapyrroles.
There are several trace elements: arsenic (As),
boron (B), chromium (Cr), molybdenum (Mo), nickel
(Ni), silicon (Si), and vanadium (V). These
elements are present in tissues at concentrations in
the range of micrograms per kilogram and have been
reported to alter some biologic process in some
species. one of the trace element is nickel we will see
in description

4. NICKEL(Ni )
Ni was first shown to promote the
growth of bacteria in 1965 (126).
The biologic importance of Ni was
subsequently shown in both
bacteria and plants to be based on
its catalytic role in four enzymes:
urease, hydrogenases, CD
dehydrogenase, and methyl-
coenzyme M reductase.
Between 1975 and 1978, diets were
developed to induce deficiency
symptoms in rats, chicks, pigs, and
goats (127–130). The nutritional
importance of Ni in humans is
unknown and remains largely
unstudied.

5. SOURCES OF Ni
Foods of plant origin have a substantially higher nickel content that
foods of animal origin. Nuts, legumes, grains, and grain products,
and chocolate are particularly rich in the metal providing upto
~228ug/100gm. Fruits and vegetables generally have intermediate
nickel content providing upto ~48ug per 100gm. Total dietary intake
of nickel by adults is typically <100ug.

6. Absorption, transport and storage
Nickel absorption from foods is thought to be <10%.
Absorption of nickel is higher from water than from other
beverages , to which nickel has been added.
Nickel is absorbed across the intestinal brush border by
a carrier and passive diffusion. In fact, nickel ions compete
with iron for carrier transport in the proximal small
intestine. Thus, absorption of nickel increases with iron
deficiency. Transport across the basolateral membrane is
thought to occur by diffusion or as part of a complex with
an amino acid or binding ligand. In the blood, nickel binds
mainly to albumin and to a lesser extent to amino acids,
including histidine, cysteine, aspartic acid.

7. Other serum proteies such as alpha-2 macroglobulin,
also may transport nickel in the blood. Uptake of nickel
into cells may occur with amino acids, with transferrin or
through a divalent cation channel such as c+2.
Although nickel is widely distributed among human
tissues, its concentration throughout the body is
extremely low, occuring at nanogram/gram levels. The
highest conc of nickel are found in the thyroid and
adrenal glands as well as in hair , bone, and soft tissues
such as the lungs, heart, kidney and liver.

8. FUNCTIONS OF NICKEL
A specific role of nickel in human and animal nutrition has
not yet been defined, although roles for nickel in plants
and microorganisms have been documented. In plants, for
example nickel serves as a cofactor for urease, which
catalyzes the hydrolysis of urea into co2 and ammonia. In
bacteria, several hydrogenases appear to be nickel
dependent. In the several enzyme systems , however, the
role of nickel can be substituted for other minerals, such as
magnesium. It has also been demonstrated that nickel can
substitute for zinc in the carboxypeptidases and in the
horse liver alcohol dehydrogenase.

9. Nickel may be involved with folate and vit B12 in the
metabolism of methionine, either in the initial stage
involving conversion to homocysteine or with vitB12 in
the later stages.
DEFICIENCY
Signs of nickel deprivation continue to be described for
some animal species. Among the more consistent signs
are depressed growth, altered distribution of some
minerals, changes in blood glucose and impaired
hematopoiesis, which probably is caused by altered iron
metabolism.

10. INTERACTIONS WITH OTHER NUTRIENTS
Because nickel shares with other metals the
property of being readily chelated by and
complexed with a wide variety of ligands, it
follows that nickel can compete with those
metal ions for ligand sites. Nickel interacts with
may ions in this manner, including as many as 13
essential minerals. The interactions of particular
nutritional interest are those involving iron , cu,
and zn.

11. EXCRETION
Most absorbed nickel is excreted in the urine in
amounts less than about 10ug/L. Within the
renal cells, nickel is first complexed with low
molecular weight compounds such as uronic
acid and neutral sugar oligosaccharides. Small
amount (1.5-3.3ug /day ) of absorbed nickel
also are excreted through the bile.

12. RECOMMENDED DIETARY INTAKE
Extrapolation from animal studies suggests that
humans probably need <100ug of nickel per
day. A tolerable upper intake level for adults for
nickel is 1.0 mg per day in the form of soluble
nickel salts (such as nickel sulfate , which may
contaminate water ).

13. Toxicity
Signs of toxicity in humans include nausea,
vomiting , and shortness of breath. In animals,
signs include lethargy, ataxia, irregular
breathing, and hypothermia, among
others ,possibly including death.

14. Thank you