Provided are crystalline forms of nicotinamide riboside, including a Form I of nicotinamide riboside chloride according to formula (I). Also disclosed are pharmaceutical compositions comprising the crystalline Form I of nicotinamide riboside chloride, and methods of producing such pharmaceutical compositions. In other aspects, the present disclosure pertains to methods comprising administering to a subject the crystalline Form I of nicotinamide riboside chloride. The present disclosure also provides methods of preparing the crystalline Form I of nicotinamide riboside chloride. Also provided are a crystalline Form I of nicotinamide riboside chloride that is prepared according to any of the disclosed methods for preparing the crystalline Form I.
