Exempt according to fass.se.
There is environmental information for folic acid from several pharmaceutical companies with the same information. Here, Fass' environmental information is presented for Cernevit (including folic acid) from Baxter (downloaded 2022-01-26).
The use of vitamins is not considered to have any environmental impact.
According to the European Medicines Agency guideline on environmental risk assessments for pharmaceuticals (EMA/CMP/SWP/4447/00) vitamins, electrolytes, amino acids, peptides, proteins, carbohydrates, lipids, vaccines and herbal medicinal products are exempted because they are unlikely to result in significant risk to the environment.
Author: Health and Medical Care Administration, Region Stockholm