What are Vitamins?

Vitamins are everywhere in the news and are often marketed as having superpowers. This week we're covering all the basics behind Vitamins: what they are, how they work, their importance, and recommended vitamin levels. This is a two part podcast so stay tuned for the next podcast where we discuss how vitamins became vitamania and how they're regulated.
// SOURCES 
Vitamania book: https://www.amazon.com/Vitamania-Vitamins-Revolutionized-Think-About/dp/0143108158
Plant vs animal vitamins:
https://www.kevinstock.io/health/vitamins-and-minerals-plants-vs-animals/
Vitamins and what they do: https://www.health.harvard.edu/staying-healthy/listing_of_vitamins
Elmer McColum: https://onwisconsin.uwalumni.com/features/the-birth-of-vitamin-a/
Vitamin D levels: https://www.health.harvard.edu/blog/vitamin-d-whats-right-level-2016121910893
Synthetic vs natural vitamins: https://www.healthline.com/nutrition/synthetic-vs-natural-nutrients#section1
Fortification/enrichment: https://www.supermarketguru.com/articles/fortification-vs-enriched-know-your-food/
Calcium/Vitamin D: 
https://www.endocrineweb.com/conditions/osteoporosis/role-calcium-vitamin-d-bone-health