7. History of severe allergy/hypersensitivity or on-going allergy/hypersensitivity, as judged by the Investigator, or history of hypersensitivity to drugs with a similar chemical structure or class to Modufolin® (i.e., folate derivatives). 8. Regular use of any prescribed or non-prescribed medication including antacids, analgesics, herbal remedies, vitamins and minerals within two weeks prior to the administration of IMP/placebo, except occasional intake of paracetamol (maximum 2000 mg/day; and not exceeding 3 000 mg/week), at the discretion of the Investigator and nasal decongestants without cortisone or antihistamine for a maximum of 10 days, at the discretion of the Investigator. 9. Regular use of any prescribed or non-prescribed medication which could influence folate and vitamin B12 status within 30 days prior to the administration of IMP/placebo.