Chromium (51,99 а.m.u.) – vital microelement. It is supposed that lack of chromium in body could be one of the reasons causing disorders of glucose tolerance. Chromium is a component of insulin and trypsin. It is bond with nucleic acids and protects them from denaturation. Development of glucose tolerance disorders and appearance of neuropathies is documented in cases of long-lasting intravenous artificial feeding with solutions of not enough concentrations of chromium. Increase of chrome concentrations restored glucose tolerance and decreased neurologic symptoms. Chromium is acting like a co-factor in process of insulin starting on the level of peripheral tissue intracellular receptors.
Chrome deficiency was discovered in cases of pancreatic diabetes of II type.
Biologically active chromium form, allegedly represents Cr3+ complex with nicotine acid, analogue to the glucose tolerance factor, discovered for brewers’ yeast. Physiological chromium effects related to lipid metabolism (with increase of concentration of cholesterol lipoproteins of high-density). Ways of metabolism and toxicity of chromium are depending on oxygenation stage. Absorption of chromium in gastro-intestinal tract is low – 0,4 – 2,5% of the total amount.
Main food source of chromium – meat, wholegrain cereals, green beans, broccoli. Cr3+ after absorption is transported in blood in complex with beta-globulins (mostly – transferrin). It is being diffusely spread in the body, excreted mostly with urine. Chromium absorption in lungs depends on solubility of chromium salts. For Cr6+ a possibility of intake through skin was demonstrated. Pure metallic chromium is non-toxic. Cr6+ is much more toxic, than Cr3+. Despite of Cr3+ compounds are comparably non-toxic, but in cases of intake of high doses, even chromium picolinate used in food supplements could cause diseases of liver and kidneys. Cr6+ is a carcinogen. Presence of Cr6+ in vapours and industrial dust could cause increased risk of lungs cancer, dermatitis, skin ulcers. Intake could lead to the appearance of giddiness, stomach pain, sickness, anuria, spasms, shock, coma.
Sources of chromium – production of steel, pigments, processing of leather, protective solutions for wood processing, photography, mixtures, used in galvanization and electrolytic surfacing and in concrete production. Pollution of soil with waste from production of paints, leathermaking plants, containing Cr6+ could be hazardous to health. It was reported that level of chromium in hair correlates with increased concentration thereof in serum and in urine in cases of professional exposition to this element. Decreased level of chromium in hair of patients with pancreatic diabetes indicated correlation with decrease of chromium level in blood serum (concentration of chromium in urine of patients with pancreatic diabetes is increased).
