The rate of sugar metabolism in the body is medicated by the hormone insulin. This regulation of blood sugar levels is not carried out by insulin alone - the mineral chromium is also involved in the process. The ability of insulin to mediate in the regulation of blood sugar cannot occur in the absence of chromium. The mineral chromium also plays vital roles in the metabolism of other bimolecular like fats, proteins and nucleic acids - DNA and RNA, aside from its main role as a co-factor in the regulation of blood sugar levels.
Chromium deficiencies have been studied in clinical experiments and a severe deficiency of the mineral was the cause for an impaired glucose tolerance - this symptom of deficiency could be as severe as a case of mild diabetes, in addition, the deficiency also induced corneal opacities in the eyes.
Physical symptom's like a raised blood level of the lipid cholesterol is also another direct effect of a chromium deficiency. Chromium deficiency also leads to a very high incidence of plaques forming along the aorta - this is the principal artery arising from the heart and supplying the rest of the body with fresh oxygenated blood. The transportation of proteins in the blood stream is also another bio-chemical process in which chromium functions as a cofactor - the metal is considered important in at least some phases of the process. Nucleic acids also interact with chromium during their bio-synthesis; this has led investigators to speculate that the metal chromium is an important co-factor in their synthesis, as well - though nucleic acids do not contain chromium as a component. The effects of very low chromium diets in animals induced problems like a depression in the growth rate, a shortening of the life span, and also produced a reduced ability to withstand physical stress. These effects could be reversed by the addition of extra chromium to the drinking water supplied to the test animals, and this addition of chromium resulted in higher growth rates and a great reduction in the death rates of the test animals. Laboratory rats and mice that were given chromium supplements actually set longitivity records by living an average of ninety nine days longer than similar animals that were not given these chromium supplements and functioned as the control group. The supplements of chromium had other benefits in that all the tested rats and mice were free of aortic plaques if they received the chromium supplement, but at least twenty percent of the rats and mice not given the chromium supplements had such lesions - even though, they were supposed to have been receiving "adequate" chromium in the normal diet.
Though many researchers and clinicians recognize the essential function of chromium in the body, at this moment there is no specific RDA for chromium - and it is simply classed amount the essential trace mineral. Chromium intakes classed as "safe" or "adequate" by The National Research Council are 0.05 to 0.2 mg daily.
GTF chromium is an abundant in the brewer's yeast - not torula - GTF stands for Glucose Tolerance Factor. Chromium is also available in high quantities in all the whole grains - with the exception of rye, in blackstrap molasses, in black pepper, in liver and cheese, in sea foods and meat, as well as nuts of all kinds. Chromium supplements are commonly available in many drug stores. The GTF chromium found in brewer's yeast is preferable over supplemental inorganic chromium salts, the chromium in the yeast is much better absorbed and utilized at a faster rate by the body.
True brewer's yeast is the best source of chromium and must be preferred over all other supplemental forms of the mineral. Chromium is not found in any significant amount in nutritional yeast and torula yeast and these are not to be considered substitutes for true brewer's yeast. Significant amounts of chromium can be found in all grains and cereals as well, however, refined grains and cereals will lack the mineral. Chromium in the majority of diets is actually sourced from stainless steel scrapings from pots and pans. Chromium is also found in significant amounts in some brands of beer - as such drinks contain a lot of yeast.
Chromium intakes by the majority of people is actually less than what is recommended by the U.S. National Academy of Science's, which is about 50 - 200 mcg of chromium per person daily. The need for most people to supplement with small amounts of chromium is suggested by many doctors of nutritional medicine due to the high incidence of adult onset diabetes today - almost at epidemic proportions.
Many doctors of nutritional medicine recommend a daily chromium intake of at least 200 mcg per person.
Toxic effects from chromium supplementation has not been consistently found to be evident when the mineral is taken in supplemental doses - at about 50 - 300 mcg per person daily, thus toxic side effects are rare if supplementation is at moderate doses. Chromium at very high concentrations caused chromosomal mutations in the ovarian cells of hamsters during test tube trails of chromium toxicity. Humans are not necessarily affected in the same way, and this risk of toxicity, has not been shown in human tissues and cells. However, at least a single report of severe illness, with problems like liver and kidney damage is known to have affected an individual, this person had taken 1,000 mcg of chromium daily for a long period of time. However, chromium supplementation was not proven to be the cause of these problems.
Toxicity from chromium supplementation has also been reported in two unrelated cases. In one person, the side effect was kidney failure, which came about following the supplemental use of 600 mcg chromium daily for a period of 6 weeks. The other person was affected by anemia, as well as liver dysfunction and other disorders that developed over 4 to 5 months of continually supplementing with 1,200 - 24,000 mcg of chromium picolinate daily. It remains unknown if these disorders were induced by supplementing with chromium picolinate, if that is so; the next question is whether the supplemental use of other forms of chromium will produce similar effects at high dosages. Unless supplementing under the supervision of a nutritionally oriented doctor, supplements of chromium exceeding 300 mcg per day must not be used by anyone - high dosage amounts must always be taken only after consulting with a doctor.