In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Physiological dose ( < 1 mg ) of folic acid both in healthy and 60 epileptic women , all without any autoimmune disease , did not increase the risk for epileptic seizures .
### Output Text:
Physiological dose ( < 1 mg ) of <span class="chemical">folic acid</span> both in healthy and 60 epileptic women , all without any autoimmune disease , did not increase the risk for epileptic seizures . 