Chromium is an essential trace mineral that helps the body maintain normal blood sugar
levels.
Where is it found?
The best source of chromium is true
brewer’s yeast. Nutritional yeast and torula yeast do not contain significant
amounts of chromium and are not suitable substitutes for brewer’s yeast. Chromium is
also found in grains and cereals, though much of it is lost when these foods
are refined. Some brands of beer contain significant amounts of chromium.
Why do athletes use it?*
Some athletes say that chromium
helps decrease body fat.
helps increase muscles.
What do the advocates say?*
Chromium is mainly used to stabilize blood sugar. The major role for chromium in weight
loss is to correct insulin resistance caused by chromium deficiency. However, assessing
chromium deficiency is difficult since normal blood levels are of such a low concentration
that they can escape detection by even the most sensitive instruments. Hair and toenail levels
can be evaluated, but are not routinely done.
Known causes of chromium deficiency include malnutrition, TPN (total parenteral nutrition),
alcoholism, and strenuous exercise, which can cause what is called “chromium
dumping.”
How much is usually taken by athletes?
Chromium, primarily in a form called chromium picolinate, has been studied for its
potential role in altering body composition. One group of researchers has reported significant
reductions in body fat in double-blind trials using 200 to 400 mcg per day of chromium for six
to twelve weeks in middle-aged adults,12 but the methods used in these
studies have been criticized.3
Are there any side effects or interactions?
In supplemental amounts (typically 50–300 mcg per day), chromium has not been found
to cause toxicity in humans. While there are a few reports of people developing medical
problems while taking chromium, a cause-effect relationship was not proven. One study
suggested that chromium in very high concentrations in a test tube could cause chromosomal
mutations in ovarian cells of hamsters.45 Chromium picolinate can be
altered by antioxidants or hydrogen peroxide
in the body to a form that could itself create free radical damage.6 In theory,
these changes could increase the risk of
cancer, but so far, chromium intake has not been linked to increased incidence of cancer
in humans.7
Chromium supplementation may enhance the effects of drugs for diabetes (e.g., insulin, blood sugar-lowering agents) and possibly
lead to hypoglycemia. Therefore, people with
diabetes taking these medications should supplement with chromium only under the supervision
of a doctor.
One report of severe illness (including
liver and kidney damage) occurring in a
person who was taking 1,000 mcg of chromium per day has been reported.8 However,
chromium supplementation was not proven to be the cause of these problems. Another source
claimed that there have been reports of mild heart
rhythm abnormalities with excessive chromium ingestion.9 However, no published
evidence supports this assertion.
Three single, unrelated cases of toxicity have been reported from use of chromium
picolinate. A case of kidney failure appeared after taking 600 mcg per day for six
weeks.10 A case of anemia, liver dysfunction, and other problems appeared after
four to five months of 1,200–2,400 mcg per day.11 A case of a muscle disease
known as rhabdomyolysis appeared in a body builder who took 1200 mcg over 48
hours.12 Whether these problems were caused by chromium picolinate or, if so,
whether other forms of chromium might have the same effects at these high amounts remains
unclear. No one should take more than 300 mcg per day of chromium without the supervision of a
doctor.
Preliminary research has found that vitamin
C increases the absorption of chromium.13
Are there any drug
interactions?
Certain medicines may interact with chromium. Refer to drug interactions for a list of those medicines.
*Athletes and fitness advocates may claim benefits for chromium based
on their personal or professional experience. These are individual opinions and testimonials
that may or may not be supported by controlled clinical studies or published scientific
articles on chromium. For more complete and detailed information, including references and
safety information, see Chromium as a nutritional
supplement.
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
1. Kaats GR, Blum K, Fisher JA, Adelman JA. Effects of chromium
picolinate supplementation on body composition: a randomized, double-masked,
placebo-controlled study. Curr Ther Res 1996;57:747–56.
2. Kaats GR, Blum K, Pullin D, et al. A randomized, double-masked,
placebo-controlled study of the effects of chromium picolinate supplementation on body
composition: a replication and extension of a previous study. Curr Ther Res
1998;59:379–88.
3. Vincent J. The potential value and toxicity of chromium picolinate as
a nutritional supplement, weight loss agent and muscle development agent. Sports Med
2003;33:213–30 [review].
4. Sterns DM, Belbruno JJ, Wetterhahn KE. A prediction of chromium (III)
accumulation in humans from chromium dietary supplements. FASEB J
1995;9:1650–7.
The information presented in Healthnotes is for informational purposes
only. It is based on scientific studies (human, animal, or in vitro), clinical
experience, or traditional usage as cited in each article. The results reported may not
necessarily occur in all individuals. For many of the conditions discussed, treatment with
prescription or over the counter medication is also available. Consult your doctor,
practitioner, and/or pharmacist for any health problem and before using any supplements or
before making any changes in prescribed medications. Information expires June 2009.
