Some links from the show:

* Vitamin A and night visions

* British Journal of Opthalmology: Night vision in a case of vitamin A deficiency due to malabsorption (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1039942/pdf/brjopthal00157-0047.pdf)

* Types of vitamin A

* National Institutes of Health: Vitamin A (https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/)

* Overdosing on vitamin A

* Wikipedia: Hypervitaminosis A (https://en.wikipedia.org/wiki/Hypervitaminosis_A)

* How vegans get B12

* PETA: Vegan B12 sources that will make you healthy in body and mind (https://www.peta.org/living/food/vegan-b12-sources-will-make-healthy-body-mind/)

* Linus Pauling's vitamin C quest

* Vox: How Linus Pauling duped America into believing vitamin C cures colds (https://www.vox.com/2015/1/15/7547741/vitamin-c-myth-pauling)

* Does vitamin C treat colds?

* Cochrane Library: Vitamin C for preventing and treating the common cold (http://cochranelibrary-wiley.com/doi/10.1002/14651858.CD000980.pub3/abstract;jsessionid=F30FC0763AD9AE151A2D080C9C223DC4.f03t01?systemMessage=Cochrane+Library+will+be+unavailable+on+Saturday+24th+March+2018+at+05.00+EDT+%2F+09%3A00+GMT+%2F+14%3A30+IST+%2F+17.00+SGT+for+3+hours+due+to+essential+maintenance.+Apologies+for+any+inconvenience.)

* WebMD: Vitamin C for the common cold (https://www.webmd.com/cold-and-flu/cold-guide/vitamin-c-for-common-cold)