| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Elsevier Science | https://linkinghub.elsevier.com/retrieve/pii/S1568-9972(19)30150-8 | |
| Vitamin D | free resource | MedlinePlus Health Information | https://medlineplus.gov/vitamind.html |
| subscription/membership/fee required | ClinicalKey | https://www.clinicalkey.com/content/playBy/pii?v=S1568-9972(19)30150-8 |