Thiamine mononitrate is synthetic and has the potential to illicit mild to severe allergic reactions.
The nitrates present in thiamine mononitrate may accumulate in the kidneys and induce kidney stones or cellular death. The University of Maryland Medical Center indicates that B vitamins are all required for optimal health of the liver, skin, eyes, hair and nervous system. Since thiamine is water-soluble, the body typically expels any excess to prevent most side effects. However, thiamine mononitrate is fat-soluble, meaning the body has more difficulty expelling any excess. Anyone with a pre-existing condition has the risk of retaining excess thiamine, which may cause potential side effects.