Chromium is a trace mineral in the body. Its role in
maintaining good health was discovered in 1957,
when scientists extracted a substance known as
glucose tolerance factor (GTF) from pork kidney.
GTF, which helps the body maintain normal blood
sugar levels, contains chromium as the active component. GTF
binds to and potentiates the activity of insulin.
Chromium is necessary for pancreatic beta cell sensitivity
(beta cells make insulin), insulin binding, insulin receptor
enzymes, and insulin receptor sites. Supplemental chromium
tends to balance glucose metabolism, benefiting both hypoglycemic
(low blood sugar) and diabetic patients. One explanation
for this is that chromium may improve C-peptide levels, leading
to enhanced pancreatic beta cell function.
Therapeutic Uses
Supplementing with chromium can lower blood lipids, which
may make it beneficial in people and pets with elevated blood
cholesterol levels. Chromium's most important function is to
help regulate the amount of glucose in the blood. Insulin regulates
the movement of glucose out of the blood and into cells.
It appears that insulin uses chromium as a cofactor to allow
glucose to pass through the cell membrane and enter the cell.
Based on chromium's close relationship with insulin, this
trace mineral has been studied as a treatment for diabetes. The
results have been positive: chromium supplements appear to
improve blood sugar control in people with diabetes.
Tissue levels of chromium in people and pets are often low
due to limited uptake of chromium by plants as well as limited
absorption by people and pets.
Scientific Evidence
Recent evidence also suggests chromium supplements might
help dieters lose fat and gain lean muscle tissue, probably
through its effects on insulin (by increasing the body's sensitivity
to insulin). Since decreased sensitivity to insulin can contribute
to weight gain (as often happens in diabetic patients),
supplying additional chromium (usually at a dose of 200 to
400 mcg/day) is recommended for weight control in people.
Research is needed to determine whether chromium would be
of benefit to overweight pets.
As mentioned, it has been theorized many Americans may
be chromium-deficient. Preliminary research done by the US
Department of Agriculture (USDA) found low chromium intakes
in a small group of people studied. Although large-scale
studies are needed to show whether Americans as a whole are
chromium-deficient, we do know many traditional sources of
chromium, such as wheat, are depleted of this important mineral
during processing. Some researchers believe inadequate intake
of chromium may be one of the causes for the rising rates
of adult-onset diabetes.
Sources of Chromium
While chromium is found in drinking water, especially hard
water, concentrations vary so widely throughout the world that
drinking water is not a reliable source. The most concentrated sources of chromium are brewer's yeast (not nutritional or torula yeast) and calf liver. Two ounces of brewer's yeast
or four ounces of calf liver supply between 50 and 60 mcg of
chromium. Other good sources of chromium are whole wheat
bread, wheat bran, and rye bread. Potatoes, wheat germ, green
pepper, and apples offer modest amounts of chromium.
Chromium Dosages for Pets
The recommended dosage for the use of chromium in pets with
diabetes is 50 to 300 mcg per day. Typically, a dosage of 200
mcg/day of chromium picolinate is recommended. However,
since picolinate may cause damage to DNA, research before
using. Using the chromium GTF natural supplement would be
a safer alternative. But you must work with your veterinarian to
determine if chromium supplementation can be used in your
pet.
Safety Issues
Calcium carbonate supplements may interfere with the absorption
of chromium.
People may have a difficult time absorbing and synthesizing
chromium if it is not attached to a substrate such as picolonic
acid (chromium picolinate) or nicotinic acid (chromium
nicotinate). In people, concerns have been raised over the use
of the picolinate form of chromium in individuals suffering from
affective or psychotic disorders, because picolinic acids can
change levels of neurotransmitters.
There has been the suggestion that chromium picolinate
may cause damage to DNA, especially when combined with
ascorbic acid. Alternative forms of chromium, such as that in
the GTF form that can be extracted from foods such as yeast,
contain no picolinic acid and may be safer. Additionally, while
many forms of chromium are available, supplementation with
an organic form (such as GTF) is recommended as the organically
bound form of chromium is absorbed better and is more
available to the pet than inorganic forms.
Chromium appears to be safe in people when taken at a
dosage of 50 to 200 mcg daily. However, concern has been expressed
since chromium is a heavy metal and might conceivably
build up and cause problems if taken to excess. There have been
a few reports of kidney damage in people who took a relatively
high dosage of chromium: 1200 mcg or more daily for several
months. For this reason, the dosage found most effective for
individuals with type II diabetes, 1000 mcg daily, might present
some health risks. Similar concerns are probably applicable for
pets.
For pets with diabetes who may respond to chromium supplementation,
a decreased dosage of insulin may be needed;
medical supervision is essential before decreasing insulin.
The maximum safe dosages of chromium for young children,
women who are pregnant or nursing, or those with severe
liver or kidney disease has not been established; similar concern
are probably warranted in pets.