Calcifediol (25-hydroxyvitamin D3) is the principal circulating form of vitamin D, used as a supplement and oral therapy for vitamin D deficiency when the hepatic 25-hydroxylation step must be bypassed or measured. Simson Pharma's Calcifediol reference standard and impurities support potency and stability testing across vitamin D supplement formulations.

Simson Pharma Global Ltd. (UK) and Simson Pharma Global LLC (USA) supply high-quality Calcifediol Reference Standards, pharmacopoeial reference materials, and its related impurities to pharmaceutical manufacturers, CROs, analytical laboratories, universities, and regulatory organizations worldwide. To service the Europe and America market efficiently, Simson Pharma Limited has set up Simson Pharma Global Ltd. in United Kingdom and Simson Pharma Global LLC in USA respectively.