Chromium Picolinate

Chromium picolinate (Cr‑P) is a chelated form of the essential trace metal chromium bound to picolinic acid, which enhances its oral absorption. It is primarily marketed as a nutritional supplement to support carbohydrate metabolism and to aid in maintaining healthy blood‑glucose levels in adults.

• Composition: Chromium picolinate is the coordination complex of trivalent chromium (Cr³⁺) with three picolinic acid ligands (2‑pyridine‑carboxylic acid).
• Molecular Formula: Its molecular formula is C₁₈H₁₂CrN₃O₆·3H₂O (anhydrous: C₁₈H₁₂CrN₃O₆).
• IUPAC Name: The IUPAC name is “tris(picolinato)chromium(III)”.
• Structure: The complex is octahedral, with each picolinate acting as a bidentate ligand (nitrogen of the pyridine ring and carboxylate oxygen) forming a stable, water‑soluble chelate.
• Molecular Weight: Molecular weight ≈ 340 g·mol⁻¹ (anhydrous).
• Solubility: It exhibits a pale‑yellow solid, soluble in water (≈5 g L⁻¹) and ethanol, and stable under neutral pH, but can hydrolyze at pH > 7.

• Synthesis: Chromium picolinate is synthesized chemically by reacting chromium(III) chloride or sulfate with picolinic acid under controlled pH and temperature, yielding a high‑purity crystalline product.
• Natural Sources: No natural food source contains picolinate‑bound chromium; dietary chromium exists as inorganic salts (e.g., chromium‑III oxide) or bound to organic ligands in whole foods (e.g., whole‑grain wheat, broccoli, nuts).
• Production: Industrial synthesis ensures consistent stoichiometry and low impurity levels, but quality varies between manufacturers.
• Quality Control: Good Manufacturing Practice (GMP)‑certified producers test for heavy‑metal contamination, residual solvents, and confirm ≥99 % purity by HPLC or ICP‑MS.
• Consumer Advice: For consumers, selecting products with third‑party certification (USP, NSF) and documented stability (e.g., sealed amber bottles) helps assure efficacy and safety.