Chromium Flashcards
What is the most important form of Chromium in humans?
Trivalent Chromium (Cr3+)
Where is Trivalent chromium (Cr3+) found?
All types of food! (best: meat, poultry, grains)
What type of yeast is known to have high concentration of Chromium?
Brewers yeast
In Brewers yeast, what is the biologically active form of Chromium found in there?
Glucose tolerance factor (GTF)
The use of what in the preparation of food is known to increase the amount of chromium in food?
Stainless steel cookware or cans
What form of Chromium is usually in supplements?
Chromium picolinate
Chromium is absorbed through what transport and what organ?
Diffusion or carrier-mediated transport in the small intestine (2% absorbed, BOGUS)
Which amino acids will act as ligands to enhance the absorption of Chromium?
Histidine, Methionine
What vitamin will enhance Chromium absorption?
Vitamin C
Generally, what will inhibit/prevent absorption of Chromium? (hint: 4 things)
- An alkaline intestinal environment
- Ingestion of antacids [decrease blood/tissue concen]
- Phytates [via chelation]
- Oxalates [via chelation]
Once Chromium is in the blood, what proteins is it transported by?
Transferrin, Albumin, Globulin
Transferrin transports chromium, this means that chromium competes with what other mineral?
Fe3+ [oxidized ferric iron]
How many mg of chromium does the human body contain?
4-6mg
What important substance in the human body is Chromium known to potentiate the action of?
Insulin [insulin is more effective in the presence of Chromium than in it’s absense]
Most recent studies on Chromium has shown that it enhances insulin’s action by doing what?
Enhancing intercellular signaling without the activation of GTF (glucose tolerance factor)
Apochromodulin is an oligopeptide composed of what four amino acids?
glycine, cysteine, glutamate, aspartate
What enzyme does Chromodulin activate?
Tyrosine kinase [this will then promote activity of insulin-activated insulin receptors] (pg. 4 diagram)
After activated by Chromodulin, Tyrosine kinase goes on to phosphorylate what secondary messenger?
Insulin Receptor Substrate (IRS)
What is Chromium bound to when it is transported through the blood?
Transferrin
When taking large doses of chromium, what effect can that have on another mineral that uses that same transporter?
It can displace the Iron being transported in the blood, which will result in a significant decrease in serum Ferritin (Fe3+)
What percentage of chromium is excreted and by what route?
95% excreted in the urine
If a patient is deficient in Chromium, what effect does this have on insulin?
Insulin resistance [hyperinsulinemia and elevated plasma glucose concen.]
Are all forms of Chromium safe to ingest?
NO!
What form of Chromium is very toxic to humans?
Hexavalent form of Chromium (Cr6+) [severe acidosis, GI hemorrhaging, liver/kidney failure]
