عدد الرسائل : 4030
العمر : 28
العمل/الترفيه : المدير
السٌّمعَة : 4
نقاط : 982
تاريخ التسجيل : 02/04/2008
|موضوع: Diabetes Mellitus - part 2 الجمعة 17 أكتوبر 2008, 22:18|| |
Safety of Chromium
Chromium comes in various forms. The dietary form is called chromium
tri-valent. This is non-toxic and necessary for essential bodily
functions. Chromium in its hexa-valent form is used in industries and
that is highly toxic.
It is extremely difficult to poison laboratory animals with oral
dietary tri-valent forms of chromium. For example, cats fed 1,000 mg of
trivalent chromium per day showed no signs of toxicity. The equivalent
daily dose for a 150 lb person would be approximately 35,000 mg per day
or 3.5 million mcg per day. In terms of the number of 200 mcg tablets,
this would be 175,000 tablets per day for a human.
"Trivalent chromium has such a low order of toxicity that deleterious
effects from excessive intake of this form of chromium do not occur
readily. Trivalent chromium becomes toxic only at extremely high
amounts - chromium then acts as a gastric irritant rather than as a
toxic element interfering with essential metabolism or biochemistry."
Modern Nutrition In Health and Disease, Eighth Ed., 1994. Shils, Olson
and Shike, eds.
The safety issue had been questioned by a study published in December
1995, which attempted to link chromosomal damage in the test tube to
oral supplementation of chromium picolinate. Researchers in this study
added unnaturally high amounts of chromium picolinate to cultured
Chinese hamster ovarian cancer. Some of these cells showed chromosomal
damage. This was not particularly surprising, since this concentration
applied was 3,000 times the blood level of people who are ingesting
chromium picolinate as supplements. It is interesting to note that
another form of chromium, chromium polynicotinate, did not have this
It is important to note that very few essential minerals tested in this
way would be found to be without toxicity. For example, merely doubling
the blood concentration of the mineral calcium is fatal to humans.
A further study was conducted by Dr. Richard Anderson, the lead
scientist for trace minerals at the U.S. Department of Agriculture's
Human Nutrition Research Center, Beltsville, Md., His research team fed
rats a stock diet . Added to the diet was 0, 5, 25, 50 or 100
micrograms (mcg) of chromium per gram of feed for a period of six
months. The supplements were added to the feed in the form of chromium
chloride or chromium picolinate. The highest supplemented level
measured approximately 1500 mcg/day per kilogram of body weight.
Translated to a human equivalent would mean that a 150 lb (70 kg)
individual would have to consume 1.05 million micrograms, or more than
5,000 tablets containing 200 mcg of chromium each daily for six months
to equal the rat intake. This study found no harmful effects in animals
supplemented with two widely used forms of dietary chromium: chromium
chloride and chromium picolinate
Forms of Chromium
There are various forms of dietary chromium. These vary in
bioavailability (absorption and retention) and biological activity
(ability to potentate and harmonize insulin). Inorganic chromium such
as chromium chloride is unfortunately poorly absorbed (0.5-2%) and has
little effect on insulin because it must first be converted into a
biologically active form, which the body has a limited ability to do.
The two most popular forms of organic chromium are niacin-bound
chromium (also called chromium polynicotinate) and chromium picolinate.
Although picolinate and polynicotinate sound alike, there are
significant differences between the two compounds.
Chromium Polynicotinate is actually a family of niacin-bound chromium
compounds. Niacin-bound chromium strongly potentiates insulin -
chromium's most vital function - while chromium picolinate is less
effective comparatively speaking.
Niacin-bound chromium such as chromium polynciotinate is also more
bioavailable than chromium picolinate. An Animal study at the
University of California found that chromium polynicotinate is better
absorbed and retained up to 311% better than chromium picolinate and
672% better than chromium chloride. Such high bioavailability means
that chromium polynicotinate can deliver more of the benefits that
chromium has to offer.
B. VITAMIN C:
As a strong antioxidant, this vitamin enhances capillary strength,
which improves blood flow. Dietary sources including leafy greens,
broccoli, peppers, oranges, and grapefruit are the primary source of
dietary vitamin C, followed by commercial supplements.
Vitamin C administration has beneficial effects on sugar and fat
metabolism in NIIDM. In a randomized double-blind cross-over study, in
which 56 diabetic patients participated, it has been established that a
supplementation of high doses of ascorbic acid (2 grams a day) markedly
improves the blood sugar regulation in patients with NIDDM. It was
recorded that the vitamin C supplementation in the NIDDM group resulted
in a statistically significant decrease of the fasting blood sugar of
10.1 to 9.1 mmol/liter. In this group the vitamin C supplement also
succeeded in lowering the level of LDL cholesterol and of triglycerides
in the blood. The greater the amount of vitamin C taken, the greater
reduction in LDL cholesterol and plasma free radicals. The plasma free
radicals are also lower compared to the placebo group. This was
reported in the Journal of the American College of Nutrition (Aug.
Vitamin C also reduces the potential of complications arising from
persistent high sugar environment in the body. Specifically, vitamin C
prevents accumulation of sorbitol (a sugar equivalent) in cells and
protect against most complications resulting from oxidation. A large
population based study found that patients with high blood levels of
Vitamin C had a lower HbA1C.
Furthermore, patients with diabetes have low levels of Vitamin C in
their cells, which can result in impaired wound healing. High dose
supplements have been shown to prevent sorbitol accumulation and
glycosilation of proteins, both of which are important factors in the
development of diabetic complications such as cataracts. 1 to 2 gram
daily of Vitamin C is recommended for diabetic patients