Name	Info	Provider	Link
Vitamin D Deficiency	free resource	MedlinePlus Health Information	https://medlineplus.gov/vitaminddeficiency.html
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/33059801/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/33059801
	free resource	Chinese Journal of Contemporary Pediatrics	http://www.zgddek.com/EN/abstract/abstract25096.shtml