Folate, absorption digestion

Formic acid can be readily absorbed from the digestive tract and the respiratory system. Systemic absorption produces acidosis, neuropathy, and visual and mental disturbances. Acidosis can also be produced when formic acid is produced by liver aldehyde dehydrogenase from formaldehyde. Formaldehyde in turn can also be produced metabolically by alcohol dehydrogenase from methanol. Formic acid is oxidized to carbon dioxide by the folate-dependent pathway. Some formic acid is excreted unchanged in the urine. 

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