FDA new food labels must include potassium content. 

Declaration of Vitamin D and potassium that will include the actual gram amount, in addition to the %DV. These are nutrients that some people are not getting enough of, which puts them at higher risk for chronic disease. The %DV for calcium and iron will continue to be required, along with the actual gram amount. Vitamins A and C will no longer be required because deficiencies of these vitamins are rare, but these nutrients can be included on a voluntary basis.

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm502182.htm

People are rarely deficient in bioactive Vitamin D.

https://en.wikipedia.org/wiki/Calcitriol. This is rarely, if ever, measured in people.