Chromium(III) picolinate

Last updated
Chromium(III) picolinate
Mer-Cr(picolinate)3enantiomers.svg
Chromax II.JPG ]]
Names
IUPAC name
Tris(picolinate)chromium(III)
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.131.423 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/3C6H5NO2.Cr/c3*8-6(9)5-3-1-2-4-7-5;/h3*1-4H,(H,8,9);/q;;;+3/p-3 Yes check.svgY
    Key: CBDQOLKNTOMMTL-UHFFFAOYSA-K Yes check.svgY
  • InChI=1/3C6H5NO2.Cr/c3*8-6(9)5-3-1-2-4-7-5;/h3*1-4H,(H,8,9);/q;;;+3/p-3
    Key: CBDQOLKNTOMMTL-DFZHHIFOAM
  • ionic form:c1ccnc(c1)C(=O)[O-].c1ccnc(c1)C(=O)[O-].c1ccnc(c1)C(=O)[O-].[Cr+3]
  • coordination form:c0ccc[n+]1c0C(=O)O[Cr-3]123(OC(=O)c0[n+]2cccc0)OC(=O)c0[n+]3cccc0
Properties
C16H12CrN3O6
Molar mass 394.283 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Chromium(III) picolinate (also trivalent chromium) is a chemical compound with the formula Cr(C5H4N(CO2))3, commonly abbreviated as CrPic3. It is a bright-red coordination compound derived from chromium(III) and picolinic acid.

Contents

Trivalent chromium occurs naturally in many foods and is one of several forms of chromium sold as a dietary supplement intended to correct chromium deficiency. However, there is no evidence of chromium deficiency in healthy people and no medical symptoms of chromium deficiency exist. [1] [2] Supplementation with trivalent chromium does not prevent or treat obesity, impaired prediabetes condition, type 2 diabetes or metabolic syndrome, and is not considered effective for maintaining or losing body weight. [1] [2]

Although daily doses of trivalent chromium up to 1,000 μg are considered to be safe, some adverse effects have been reported, and there is no clinical evidence that chromium supplementation provides any health benefit. [1] [2]

History

Although some research suggested that chromium(III) picolinate may assist in weight loss and increase muscle mass, a 2013 Cochrane review was unable to find "reliable evidence to inform firm decisions" to support such claims. [3]

Among the transition metals, Cr3+ is the most controversial in terms of nutritional value and toxicity. [4] [5] Furthermore, this controversy is amplified by the fact that no chromium-containing biomolecules have had their structure characterized, nor has the mode of action been determined. The first experiment that led to the discovery of Cr3+ playing a role in glucose metabolism proposed that the biologically active form of the metal existed in a protein called glucose tolerance factor , but further research indicated it is simply an artifact obtained from isolation procedures. [4] [6] [7] The only accepted indicator of chromium deficiency is the reversal of symptoms that occurs when chromium(III) supplementation is administered in pharmacological doses to people on total parenteral nutrition. [1] [8]

Physicochemical properties

Rotating video file of chromium picolinate coordination chemistry and molecular geometry Chromium picolinate3.gif
Rotating video file of chromium picolinate coordination chemistry and molecular geometry

Chromium(III) picolinate is a pinkish-red compound and was first reported in 1917. [9] It is poorly soluble in water, having a solubility of 600 μM in water at near neutral pH. [5] Similar to other chromium(III) compounds, it is relatively inert and unreactive, meaning that this complex is stable at ambient conditions and high temperatures are required to decompose the compound. [10] At lower pH levels, the complex hydrolyzes to release picolinic acid and free Cr3+. [5]

Structure

Chromium(III) picolinate has a distorted octahedral geometry and is isostructural to cobalt (III) and manganese (III) counterparts. [11] [12] Chromium(III) is a hard lewis acid and as such has high affinity to the carboxylate oxygen and medium affinity to the pyridine nitrogen of picolinate. [11] [13] Each picolinate ligand acts as a bidentate chelating agent and neutralizes the +3 charge of Cr3+. Evidence that the Cr3+ center coordinates to the pyridine nitrogen comes from a shift in the IR spectra of a C=N vibration at 1602.4 cm−1 for free picolinic acid to 1565.9 cm−1 for chromium(III) picolinate. [11] The bond length between Cr3+ and the nitrogen atom of the pyridine ring on picolinate ranges from 2.047 to 2.048 Å. [12] The picolinate ligand coordinates to Cr3+ only when deprotonated and this is evident by the disappearance of IR bands ranging from 2400 to 2800 cm−1 (centered at 2500 cm−1) and 1443 cm−1, corresponding to the O-H stretching and bending, respectively, on the carboxyl functional group. [10] [11] Furthermore, this IR shift also indicates that only one oxygen atom from the carboxylate of picolinate coordinates to the Cr3+ center. [10] [11] [13] The Cr-O bond length ranges from 1.949 to 1.957 Å. [12] The crystal structure has only been recently described in 2013. [13] Water does not coordinate to the Cr3+ center and is instead thought to hydrogen bond between other Cr(Pic)3 complexes to form a network of Cr(Pic)3 complexes. [13]

Biochemistry of chromium(III) picolinate

Chromium was once proposed as an essential nutrient in maintaining normal blood glucose levels, [6] but this function has not been sufficiently demonstrated. [1] [2] The European Food Safety Authority concluded that there is no convincing evidence to show chromium as an essential nutrient, thereby not justifying the setting of recommendations for chromium dietary intake. [14]

Absorption and excretion of chromium(III) picolinate

Once chromium(III) picolinate is ingested and enters the stomach, acidic hydrolysis of the complex occurs when in contact with the stomach mucosa. [15] The hydrolyzed Cr3+ is present in the hexaaqua form and polymerizes to form an insoluble Cr(III)-hydroxide-oxide (the process of olation) once it reaches the alkaline pH of the small intestine. [16] Approximately 2% of Cr3+ is absorbed through the gut as chromium(III) picolinate via unsaturated passive transport. [9] Although absorption is low, CrPic3 absorbs more efficiently than other organic and inorganic sources (i.e. CrCl3 and chromium nicotinate) and thus accumulate at higher concentrations in tissues. [7] [17] This has been one major selling point for chromium(III) picolinate over other chromium(III) supplements. Organic sources tend to absorb better as they have ligands which are more lipophilic and usually neutralize the charge of the metal, thus permitting for easier passage through the intestinal membrane. [17]

It has also been shown that dietary factors affect Cr3+ absorption. Starch, simple sugars, oxalic acid, and some amino acids tend to increase the rate of absorption of chromium(III). This is a result of ligand chelation, converting hexaaqua Cr3+ into more lipophilic forms. [17] In contrast, calcium, magnesium, titanium, zinc, vanadium, and iron reduce the rate of absorption. [17] Presumably, these ions introduce new metal-ligand equilibria, thus decreasing the lipophilic ligand pool available to Cr3+. Once absorbed into the bloodstream, 80% of the Cr3+ from CrPic3 is passed along to transferrin. [15] [17] [18] The exact mechanism of release is currently unknown, however, it is believed not to occur by a single electron reduction, as in the case of Fe3+, due to the high instability of Cr2+. [16] Administered Cr3+ can be found in all tissues ranging from 10 to 100 μg/kg body weight. [17] It is excreted primarily in the urine (80%) while the rest is excreted in sweat and feces. [17]

Binding of chromium(III) to transferrin

The 2 binding sites of transferrin. When iron saturation is high, Cr can compete with Fe for binding to the C-lobe. Transferrin binding sites.png
The 2 binding sites of transferrin. When iron saturation is high, Cr can compete with Fe for binding to the C-lobe.

Transferrin, in addition to chromodulin has been identified as a major physiological chromium transport agent, [18] [20] although a recent study found that Cr3+ in fact disables transferrin from acting as a metal ion transport agent. [21] While transferrin is highly specific for ferric ions, at normal conditions, only 30% of transferrin molecules are saturated with ferric ions, allowing for other metals, particularly those with a large charge to size ratio, to bind as well. [5] [9] [19] The binding sites consist of a C-lobe and an N-lobe which are nearly identical in structure. [19] Each lobe contains aspartic acid, histidine, 2 tyrosine residues and a bicarbonate ion that acts as a bidentate ligand to allow iron or other metals to bind to transferrin in a distorted octahedral geometry. [18] [19] [20] Evidence supporting the binding of Cr3+ to transferrin comes from extensive clinical studies that showed a positive correlation between levels of ferritin and of fasting glucose, insulin, and glycated hemoglobin (Hb1Ac) levels. [5] Furthermore, an in vivo study in rats showed that 80% of isotopically labelled Cr3+ ended up on transferrin while the rest were bound to albumin. An in vitro study showed that when chromium(III) chloride was added to isolated transferrin, the Cr3+ readily bound transferrin, owing to changes in the UV-Vis spectrum. [9] [18] [22] The formation constant for Cr3+ in the C-lobe is 1.41 x 1010 M−1 and 2.04 x 105 M−1 in the N-lobe, which indicates that Cr3+ preferentially binds the C-lobe. [5] [18] [19] Overall, the formation constant for chromium(III) is lower than that of the ferric ion. [18] The bicarbonate ligand is crucial in binding Cr3+ as when bicarbonate concentrations are very low, the binding affinity is also significantly lower. [18] Electron paramagnetic resonance (EPR) studies have shown that below pH 6, chromium(III) binds only to the N-lobe and that at near neutral pH, chromium(III) binds to the C-lobe as well. [5] Chromium(III) can compete with the ferric ion for binding to the C-lobe when the saturation greatly exceeds 30%. [19] As such, these effects are only seen in patients with hemochromatosis, an iron-storage disease characterized by excessive iron saturation in transferrin. [22]

Mechanism of action

This diagram shows the insulin pathway and its role in regulating blood glucose levels Regulation of glycogen metabolism insulin.svg
This diagram shows the insulin pathway and its role in regulating blood glucose levels

The precise composition and structure of the form of chromium having biological activity is not known. [2]

Low-molecular-weight chromium-binding substance (LMWCr; also known as chromodulin) is an oligopeptide that seems to bind chromium(III) in the body. [23] It consists of four amino acid residues; aspartate, cysteine, glutamate, and glycine, bonded with four (Cr3+) centers. [5] [8] [24] In vitro, it interacts with the insulin receptor by prolonging kinase activity through stimulating the tyrosine kinase pathway, although this effect has not been adequately shown in vivo. [1] [2] [25]

Oxidation of a cysteine residue to sulfenic acid Oxidation of a Cys residue to sulfenic acid by chromium species.jpg
Oxidation of a cysteine residue to sulfenic acid

Health claims

Body weight

Although chromium(III) picolinate has been marketed in the United States as an aid to body development for athletes, and as a means of losing weight, there is insufficient evidence that it provides this effect. Reviews have reported either no effect on either muscle growth or fat loss, [26] or a small weight loss in trials longer than 12 weeks, preventing a conclusion about a positive effect of chromium supplementation. [3] The European Food Safety Authority reviewed the literature and concluded that there was insufficient evidence to support a claim of effect on body weight. [14]

Diabetes

Although there were claims that trivalent chromium supplementation aids in reducing insulin resistance, particularly in type 2 diabetes, reviews showed no association between chromium supplementation and glucose or insulin concentrations. [2] [27] [28] [29] Two reviews concluded that chromium(III) picolinate may be more effective at lowering blood glucose levels compared to other chromium-containing dietary supplements. [28] [30]

In 2005, the U.S. Food and Drug Administration (FDA) approved a qualified health claim for chromium picolinate as a dietary supplement relating to insulin resistance and risk of type 2 diabetes. Any company wishing to make such a claim must use the exact wording: "One small study suggests that chromium picolinate may reduce the risk of insulin resistance, and therefore possibly may reduce the risk of type 2 diabetes. FDA concludes, however, that the existence of such a relationship between chromium picolinate and either insulin resistance or type 2 diabetes is highly uncertain." As part of the petition review process, the FDA rejected other claims for reducing abnormally elevated blood sugar, risk of cardiovascular disease, risk of retinopathy or risk of kidney disease. [31] In 2006, the FDA added that the "relationship between chromium(III) picolinate intake and insulin resistance is highly uncertain". [32]

Safety and toxicity

There is little evidence that trivalent chromium in typical supplement amounts causes toxicity in humans. [2] Oral use of chromium is considered to be relatively safe because ingested chromium is poorly absorbed and the amount absorbed is rapidly excreted. [2]

Use of chromium picolinate may cause an allergic reaction, headache, insomnia, or irritability, and may interfere with normal thinking and muscular coordination. [33] It has possible interactions with dozens of prescription drugs and other supplements. [34]

Diabetic people who take insulin should not use chromium picolinate, as it may adversely affect insulin levels and control of blood glucose. [33] Chromium picolinate should not be used while pregnant or during breastfeeding. [33]

Although the safety of daily chromium doses of up to 1,000 μg has been shown, there are some reports of serious adverse effects by using chromium picolinate, including kidney failure from a six-week course of 600 μg per day and liver disease after using 1,200 to 2,400 μg per day over four to five months. [2]

Regulation of chromium(III) picolinate

In 2004, the UK Food Standards Agency advised consumers to use other forms of trivalent chromium in preference to chromium(III) picolinate until specialist advice was received from the Committee on Mutagenicity. This was due to concerns raised by the Expert Group on Vitamins and Minerals that chromium(III) picolinate might be genotoxic (cause cancer). The committee also noted two case reports of kidney failure that might have been caused by this supplement and called for further research into its safety. [35] [36] In December 2004, the Committee on Mutagenicity published its findings, which concluded that "overall it can be concluded that the balance of the data suggest that chromium(III) picolinate should be regarded as not being mutagenic in vitro" and that "the available in-vivo tests in mammals with chromium(III) picolinate are negative". [37] Following these findings, the UK Food Standards Agency withdrew its advice to avoid chromium(III) picolinate, though it plans to keep its advice about chromium supplements under review. [38]

In 2010, chromium(III) picolinate was approved by Health Canada to be used in dietary supplements. Approved labeling statements include: a factor in the maintenance of good health, provides support for healthy glucose metabolism, helps the body to metabolize carbohydrates and helps the body to metabolize fats. [39]

Related Research Articles

<span class="mw-page-title-main">Chromium</span> Chemical element with atomic number 24 (Cr)

Chromium is a chemical element; it has symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.

<span class="mw-page-title-main">Carbohydrate</span> Organic compound that consists only of carbon, hydrogen, and oxygen

A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 and thus with the empirical formula Cm(H2O)n, which does not mean the H has covalent bonds with O. However, not all carbohydrates conform to this precise stoichiometric definition, nor are all chemicals that do conform to this definition automatically classified as carbohydrates.

<span class="mw-page-title-main">Insulin</span> Peptide hormone

Insulin is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (INS) gene. It is the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats, and protein by promoting the absorption of glucose from the blood into cells of the liver, fat, and skeletal muscles. In these tissues the absorbed glucose is converted into either glycogen, via glycogenesis, or fats (triglycerides), via lipogenesis; in the liver, glucose is converted into both. Glucose production and secretion by the liver are strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is thus an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules in the cells. Low insulin in the blood has the opposite effect, promoting widespread catabolism, especially of reserve body fat.

Insulin resistance (IR) is a pathological condition in which cells in insulin-sensitive tissues in the body fail to respond normally to the hormone insulin or downregulate insulin receptors in response to hyperinsulinemia.

<span class="mw-page-title-main">Dietary fiber</span> Portion of plant-derived food that cannot be completely digested

Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition and can be grouped generally by their solubility, viscosity and fermentability which affect how fibers are processed in the body. Dietary fiber has two main subtypes: soluble fiber and insoluble fiber which are components of plant-based foods such as legumes, whole grains, cereals, vegetables, fruits, and nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases. Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulin, lignins, chitins, pectins, beta-glucans, and oligosaccharides.

<span class="mw-page-title-main">Mineral (nutrient)</span> Chemical element required as an essential nutrient by organisms to perform life functions

In the context of nutrition, a mineral is a chemical element. Some "minerals" are essential for life, but most are not. Minerals are one of the four groups of essential nutrients; the others are vitamins, essential fatty acids, and essential amino acids. The five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium. The remaining minerals are called "trace elements". The generally accepted trace elements are iron, chlorine, cobalt, copper, zinc, manganese, molybdenum, iodine, and selenium; there is some evidence that there may be more.

<span class="mw-page-title-main">Transferrin</span> Mammalian protein found in Homo sapiens

Transferrins are glycoproteins found in vertebrates which bind and consequently mediate the transport of iron (Fe) through blood plasma. They are produced in the liver and contain binding sites for two Fe3+ ions. Human transferrin is encoded by the TF gene and produced as a 76 kDa glycoprotein.

<span class="mw-page-title-main">Chrome plating</span> Technique of electroplating

Chrome plating is a technique of electroplating a thin layer of chromium onto a metal object. A chrome plated part is called chrome, or is said to have been chromed. The chromium layer can be decorative, provide corrosion resistance, facilitate cleaning, and increase surface hardness. Sometimes a less expensive substitute for chrome, such as nickel, may be used for aesthetic purposes.

<span class="mw-page-title-main">Chromate and dichromate</span> Chromium(VI) anions

Chromate salts contain the chromate anion, CrO2−
4. Dichromate salts contain the dichromate anion, Cr
2O2−
7. They are oxyanions of chromium in the +6 oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible.

<span class="mw-page-title-main">Insulin receptor</span> Cell receptor found in humans

The insulin receptor (IR) is a transmembrane receptor that is activated by insulin, IGF-I, IGF-II and belongs to the large class of receptor tyrosine kinase. Metabolically, the insulin receptor plays a key role in the regulation of glucose homeostasis; a functional process that under degenerate conditions may result in a range of clinical manifestations including diabetes and cancer. Insulin signalling controls access to blood glucose in body cells. When insulin falls, especially in those with high insulin sensitivity, body cells begin only to have access to lipids that do not require transport across the membrane. So, in this way, insulin is the key regulator of fat metabolism as well. Biochemically, the insulin receptor is encoded by a single gene INSR, from which alternate splicing during transcription results in either IR-A or IR-B isoforms. Downstream post-translational events of either isoform result in the formation of a proteolytically cleaved α and β subunit, which upon combination are ultimately capable of homo or hetero-dimerisation to produce the ≈320 kDa disulfide-linked transmembrane insulin receptor.

<span class="mw-page-title-main">Chromium(III) chloride</span> Chemical compound

Chromium(III) chloride (also called chromic chloride) is an inorganic chemical compound with the chemical formula CrCl3. It forms several hydrates with the formula CrCl3·nH2O, among which are hydrates where n can be 5 (chromium(III) chloride pentahydrate CrCl3·5H2O) or 6 (chromium(III) chloride hexahydrate CrCl3·6H2O). The anhydrous compound with the formula CrCl3 are violet crystals, while the most common form of the chromium(III) chloride are the dark green crystals of hexahydrate, CrCl3·6H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.

Chromium deficiency is described as the consequence of an insufficient dietary intake of the mineral chromium. Chromium was first proposed as an essential element for normal glucose metabolism in 1959, but its biological function has not been identified. Cases of deficiency were described in people who received all of their nutrition intravenously for long periods of time.

<span class="mw-page-title-main">Nutrition and pregnancy</span> Nutrient intake and dietary planning undertaken before, during and after pregnancy

Nutrition and pregnancy refers to the nutrient intake, and dietary planning that is undertaken before, during and after pregnancy. Nutrition of the fetus begins at conception. For this reason, the nutrition of the mother is important from before conception as well as throughout pregnancy and breastfeeding. An ever-increasing number of studies have shown that the nutrition of the mother will have an effect on the child, up to and including the risk for cancer, cardiovascular disease, hypertension and diabetes throughout life.

<span class="mw-page-title-main">Branched-chain amino acid</span> Amino acid with a branched carbon chain

A branched-chain amino acid (BCAA) is an amino acid having an aliphatic side-chain with a branch. Among the proteinogenic amino acids, there are three BCAAs: leucine, isoleucine, and valine. Non-proteinogenic BCAAs include 2-aminoisobutyric acid and alloisoleucine.

<span class="mw-page-title-main">Chromium(III) nicotinate</span> Chemical compound

Chromium(III) nicotinate is an ionic substance used for chromium supplementation in some nutritional products, where it is also referred to as chromium polynicotinate. It appears in products that are referred to as a medical food used for nutritional support for conditions associated with diabetes mellitus type 2. The product is also known as "niacin-bound chromium".

Chromium toxicity refers to any poisonous toxic effect in an organism or cell that results from exposure to specific forms of chromium—especially hexavalent chromium. Hexavalent chromium and its compounds are toxic when inhaled or ingested. Trivalent chromium is a trace mineral that is essential to human nutrition. There is a hypothetical risk of genotoxicity in humans if large amounts of trivalent chromium were somehow able to enter living cells, but normal metabolism and cell function prevent this.

Low-molecular-weight chromium-binding substance (LMWCr; also known as chromodulin) is an oligopeptide that seems to transport chromium in the body. It consists of four amino acid residues; aspartate, cysteine, glutamate, and glycine, bonded with four (Cr3+) centers. It interacts with the insulin receptor, by prolonging kinase activity through stimulating the tyrosine kinase pathway, thus leading to improved glucose absorption. and has been confused with glucose tolerance factor.

Phonemic neurological hypochromium therapy (PNHT) is a technique that uses insemination devices to implement chromium (Cr3+) into the hypothalamic regions of the brain. It has been proposed by Dr. Nicole Kim to offset delayed phonemic awareness in children between the ages of 3 and 8. The causes of delayed phonemic awareness have been linked to an inability to break down chromium triastenitephosphate. PNHT has been successfully implemented into in vivo mice with some controversial side effects, including; polydactyly, regurgitation, fatigue, and nausea. While Russia, Poland, and Ukraine have approved this procedure, the United States Food and Drug Administration (USFDA) has not yet granted its approval.

The insulin transduction pathway is a biochemical pathway by which insulin increases the uptake of glucose into fat and muscle cells and reduces the synthesis of glucose in the liver and hence is involved in maintaining glucose homeostasis. This pathway is also influenced by fed versus fasting states, stress levels, and a variety of other hormones.

Chromium is claimed to be an essential element involved in the regulation of blood glucose levels within the body. More recent reviews have questioned this, however.

References

  1. 1 2 3 4 5 6 "Chromium". Office of Dietary Supplements, US National Institutes of Health. 2 June 2022. Retrieved 17 October 2024.
  2. 1 2 3 4 5 6 7 8 9 10 "Chromium". Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis. January 2024. Retrieved 17 October 2024.
  3. 1 2 Tian, H; Guo, X; Wang, X; He, Z; Sun, R; Ge, S; Zhang, Z (2013). "Chromium picolinate supplementation for overweight or obese adults". The Cochrane Database of Systematic Reviews. 2013 (11): CD010063. doi:10.1002/14651858.CD010063.pub2. PMC   7433292 . PMID   24293292. CD010063.
  4. 1 2 Levina, Aviva; Lay, Peter (2008). "Chemical Properties and Toxcity of Chromium (III) Nutritional Supplements". Chemical Research in Toxicology. 21 (3): 563–571. doi:10.1021/tx700385t. PMID   18237145.
  5. 1 2 3 4 5 6 7 8 Feng, Weiyue (2007). "Chapter 6 – The Transport of chromium (III) in the body: Implications for Function" (PDF). In Vincent, John (ed.). The Nutritional Biochemistry of Chromium (III). Amsterdam: Elsevier B.V. pp. 121–137. ISBN   978-0444530714 . Retrieved 20 March 2015.[ permanent dead link ]
  6. 1 2 Cefalu, William; Hu, Frank (2004). "Role of Chromium in Human Health and in Diabetes". Diabetes Care. 27 (11): 2741–2751. doi: 10.2337/diacare.27.11.2741 . PMID   15505017 . Retrieved 20 March 2015.
  7. 1 2 Anderson, Richard (1998). "Chromium, Glucose Intolerance and Diabetes". Journal of the American College of Nutrition. 17 (6): 548–555. doi:10.1080/07315724.1998.10718802. PMID   9853533. S2CID   19532052.
  8. 1 2 Vincent, John (2004). "Recent advances in the nutritional biochemistry of trivalent chromium". Proceedings of the Nutrition Society. 63 (1): 41–47. doi: 10.1079/PNS2003315 . PMID   15070438.
  9. 1 2 3 4 Vincent, John (2001). "The Bioinorganic Chemistry of Chromium (III)". Polyhedron. 20 (1–2): 1–26. doi:10.1016/S0277-5387(00)00624-0.
  10. 1 2 3 Abou–Gamra, Zeinab; Abdel–Messih, Michel (2014). "Correlation of thermal and spectral properties of chromium(III) picolinate complex and kinetic study of its thermal degradation". Journal of Thermal Analysis and Calorimetry. 117 (2): 993–1000. doi:10.1007/s10973-014-3768-5. S2CID   93050541.
  11. 1 2 3 4 5 Parajón–Costa, Beatriz; Wagner, Claudia; Baran, Enrique (2003). "Voltammetric and Spectroscopic Study of Chromium(III)/Picolinate Complexes". Zeitschrift für Anorganische und Allgemeine Chemie. 629 (6): 1085–1090. doi:10.1002/zaac.200300050.
  12. 1 2 3 Stearns, Diane; Armstrong, William (1992). "Mononuclear and binuclear chromium(III) picolinate complexes". Inorganic Chemistry. 31 (25): 5178–5184. doi:10.1021/ic00051a007.
  13. 1 2 3 4 Hakimi, Mohammad (2013). "Structural and Spectral Characterization of a Chromium (III) Picolinate Complex: Introducing a New Redox Reaction". Journal of the Korean Chemical Society. 57 (6): 721–725. doi: 10.5012/jkcs.2013.57.6.721 . Retrieved 1 April 2015.
  14. 1 2 "Scientific Opinion on the substantiation of health claims related to chromium and contribution to normal macronutrient metabolism (ID 260, 401, 4665, 4666, 4667), maintenance of normal blood glucose concentrations (ID 262, 4667), contribution to the maintenance or achievement of a normal body weight (ID 339, 4665, 4666), and reduction of tiredness and fatigue (ID 261) pursuant to Article 13(1) of Regulation (EC) No 1924/2006". EFSA Journal. 8 (10). 2010. doi: 10.2903/j.efsa.2010.1732 .
  15. 1 2 Lukaski, Henry (2007). "Chapter 4 –Effects of Chromium(III) as a nutritional supplement" (PDF). In Vincent, John (ed.). The Nutritional Biochemistry of Chromium (III). Amsterdam: Elsevier B.V. pp. 57–70. ISBN   978-0444530714 . Retrieved 20 March 2015.[ permanent dead link ]
  16. 1 2 Laschinsky, Niels; Kottwitz, Karin; Freund, Barbara; Dresow, bernd; Fischer, Roland; Nielsen, Peter (2012). "Bioavailability of chromium(III)-supplements in rats and humans". BioMetals. 25 (5): 1051–1060. doi:10.1007/s10534-012-9571-5. PMID   22814636. S2CID   1533593.
  17. 1 2 3 4 5 6 7 Debski, B.; Goniewicz, M.; Krzyzowskal, M.; Lewicka, A.; Lewickil, S.; Niemcewiz, M.; Zdanowskil, R. (2014). "The role of Chromium III in the organism and its possible use in diabetes and obesity treatment". Annals of Agricultural and Environmental Medicine. 21 (2): 331–335. doi: 10.5604/1232-1966.1108599 . PMID   24959784.
  18. 1 2 3 4 5 6 7 Vincent, John (2015). "Is the Pharmacological Mode of Action of Chromium (III) as a secondary messenger?". Biological Trace Element Research. 166 (1): 7–12. doi:10.1007/s12011-015-0231-9. PMID   25595680. S2CID   16895342.
  19. 1 2 3 4 5 6 Quarles, C.; Marcus, R.; Brumaghim, Julia (2011). "Competitive binding of Fe3+, Cr3+, and Ni2+ to transferrin". Journal of Biological Inorganic Chemistry. 16 (6): 913–921. doi:10.1007/s00775-011-0792-9. PMID   21678080. S2CID   24302252.
  20. 1 2 Vincent, John (2012). "The binding and transport of alternative metals by transferrin". Biochimica et Biophysica Acta (BBA) - General Subjects. 1820 (3): 362–378. doi:10.1016/j.bbagen.2011.07.003. PMID   21782896.
  21. ↑ Levina, Aviva; Pham, T. H. Nguyen; Lay, Peter A. (2016-05-01). "Binding of Chromium(III) to Transferrin Could be Involved in Detoxification of Dietary Chromium(III) Rather Than Transport of an Essential Trace Element". Angewandte Chemie International Edition. 55 (28): 8104–8107. doi: 10.1002/anie.201602996 . ISSN   1521-3773. PMID   27197571.
  22. 1 2 Vincent, John (2012). "Biochemical Mechanisms". In Vincent, John (ed.). The Bioinorganic Chemistry of Chromium. Chichester, UK: John Wiley & Sons. pp. 125–167. doi:10.1002/9781118458891.ch6. ISBN   978-0470664827.
  23. ↑ Viera M, Davis-McGibony CM (2008). "Isolation and characterization of low-molecular-weight chromium-binding substance (LMWCr) from chicken liver". Protein J. 27 (6): 371–375. doi:10.1007/s10930-008-9146-z. PMID   18769887. S2CID   32564084.
  24. ↑ Vincent, John (2000). "The Biochemistry of Chromium". The Journal of Nutrition. 130 (4): 715–718. doi: 10.1093/jn/130.4.715 . PMID   10736319.
  25. ↑ Vincent JB (1994). "Relationship between glucose tolerance factor and low-molecular-weight chromium-binding substance" (PDF). Journal of Nutrition. 124 (1): 117–9. doi:10.1093/jn/124.1.117. PMID   8283288.
  26. ↑ Vincent J.B.; Sack, DA; Roffman, M; Finch, M; Komorowski, JR (2003). "The potential value and toxicity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent". Sports Medicine. 33 (3): 213–230. doi:10.2165/00007256-200333030-00004. PMID   12656641. S2CID   9981172.
  27. ↑ Althuis MD, Jordan NE, Ludington EA, Wittes JT (1 July 2002). "Glucose and insulin responses to dietary chromium supplements: a meta-analysis". American Journal of Clinical Nutrition. 76 (1): 148–155. doi: 10.1093/ajcn/76.1.148 . PMID   12081828.
  28. 1 2 Balk EM, Tatsioni A, Lichtenstein AH, Lau J, Pittas AG (2007). "Effect of chromium supplementation on glucose metabolism and lipids: a systematic review of randomized controlled trials". Diabetes Care. 30 (8): 2154–2163. doi: 10.2337/dc06-0996 . PMID   17519436.
  29. ↑ Suksomboon, N.; Poolsup, N.; Yuwanakom, A. (2014). "Systematic review and meta-analysis of the efficacy and safety of chromium supplementation in diabetes". Journal of Clinical Pharmacy and Therapeutics. 39 (3): 292–306. doi: 10.1111/jcpt.12147 . PMID   24635480. S2CID   22326435.
  30. ↑ Broadhurst CL, Domenico P (December 2006). "Clinical studies on chromium picolinate supplementation in diabetes mellitus – a review". Diabetes Technol. Ther. 8 (6): 677–87. doi:10.1089/dia.2006.8.677. PMID   17109600.
  31. ↑ Qualified Health Claims: Letter of Enforcement Discretion – Chromium Picolinate and Insulin Resistance (Docket No. 2004Q-0144) (2005) U.S. Food and Drug Administration.
  32. ↑ Trumbo PR, Ellwood KC (August 2006). "Chromium picolinate intake and risk of type 2 diabetes: an evidence-based review by the United States Food and Drug Administration". Nutr. Rev. 64 (8): 357–63. doi: 10.1111/j.1753-4887.2006.tb00220.x . PMID   16958312.
  33. 1 2 3 "Chromium picolinate". Drugs.com. 16 August 2023. Retrieved 19 October 2024.
  34. ↑ "Chromium picolinate drug interactions". Drugs.com. 2024. Retrieved 19 October 2024.
  35. ↑ Safe Upper Levels for Vitamins and Minerals Archived 2008-07-04 at the Wayback Machine Food Standards Agency – May 2003
  36. ↑ Risk assessment: Chromium Expert Group on Vitamins and Minerals, 2003
  37. ↑ Statement on the Mutagenicity of Trivalent Chromium and Chromium Picolinate Archived 2008-05-16 at the Wayback Machine COM/04/S3 - December 2004
  38. ↑ Agency revises chromium picolinate advice Food Standards Agency - 13 December 2004
  39. ↑ "Monograph: Chromium (from Chromium picolinate)". Health Canada. December 9, 2009. Retrieved March 24, 2015.
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