| Name | Info | Provider | Link |
|---|---|---|---|
| Folic Acid | free resource | MedlinePlus Health Information | https://medlineplus.gov/folicacid.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=14615465.ui | |
| subscription/membership/fee required | Wiley | https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0091-2700&date=2003&volume=43&issue=12&spage=1299 |