Purity ~80%. Vitamin D3 isomer. Vitamin D3 mediates intestinal calcium absorbtion, bone calcium metabolism and many other processes. During exposure to sunlight 7-dehydrocholesterol in converted to pre-vitamin D3, which undergoes a rapid transformation within the plasma membrane to vitamin D3. Solubility: As Reported Atmosphere: Inert Gas Method for Determining Identity: Proton NMR (CDCl3) and Mass Spectrometric Analysis TLC Conditions: As Reported