História da "Vitamina" D e necessidade ou não da suplementação

Depois das notícias (p.e. da Time) sobre como evitar constipações (R: Tomando vitamina D), algumas críticas à recomendação e um pouco de história:
https://www.theatlantic.com/health/archive/2017/02/definitive-vitamin-d/517302/

Citando:
"The scientific process behind the health claims was ethically fraught, too, in that it came from University of Wisconsin researchers who owned the patent on producing the compound that had recently been named “vitamin D.” The term started as a colloquialism for what chemists know as cholecalciferol and ergocalciferol, which are not structurally or functionally similar to the other compounds widely known as “vitamins.”

D is technically a pre-hormone involved in multiple metabolic processes but mainly known to affect the levels of calcium and phosphorus in our bodies. Though little was known in the 1930s about exactly how “vitamin D” worked to prevent people’s bones from warping, the biochemist who patented the process of synthesizing the compound said, “If the public should demand vitamin D in its beer, there is no reason why [we] should not provide it.”

The demanding people weren’t ready for vitamin beer, apparently, and Schlitz took it off the market two years later. Instead cow’s milk became the delivery vehicle for vitamin D supplements in the United States. A milk-fortification law was passed to combat the scourge of rickets. So arose the belief that drinking cow’s milk was necessary for strong bones. As the dairy industry made the case in government-sponsored advertising, vitamin D actually became a primary selling point for milk—the reason that many Americans believe drinking cow’s milk is necessary still today. (Even though adult cows don’t drink it.)"