Oat milk is a type of plant milk made of oats and water blended together, and contains more vitamin B than other milk alternatives. Milk alternatives—especially oat milk—have become extremely popular the past few years because of the uptick in non-dairy diets advertised on TV and social media. Even people who aren’t lactose intolerant regularly purchase oat milk—if everyone on the internet is talking about it, it must be good (social proof).