| Name | Info | Provider | Link |
|---|---|---|---|
| Vitamin D | free resource | MedlinePlus Health Information | https://medlineplus.gov/vitamind.html |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=15860047.ui | |
| subscription/membership/fee required | Wiley | https://doi.org/10.1111/j.1365-2362.2005.01492.x |