Name	Info	Provider	Link
Calcium	free resource	MedlinePlus Health Information	https://medlineplus.gov/calcium.html
Cited by Patents in	free resource	The Lens - Patent Citations Database	https://www.lens.org/lens/search/patent/list?q=reference_cited.nlp.ids.pmid:10799379
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/ajcn/article-lookup/doi/10.1093/ajcn/71.5.1166