Name	Info	Provider	Link
Vitamin A	free resource	MedlinePlus Health Information	https://medlineplus.gov/vitamina.html
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0024-4201&date=1980&volume=15&issue=3&spage=157