As a group of people who spend large amounts of time infront of a computer and not outdoors we're all particularly vulnerable to deficits in vitamin D.
It's hacking the body!
At least the Soylent thing more or less died off. In a way it's comforting to know that the übermenschen on HN are as fad-prone as anyone.
It died off because it's more commonplace now. Lots of people are taking meal replacements.