 Shares of ChromaDex Corp. shot up 12.8 in premarket trading Monday, after the maker of healthy aging supplements said its Tru Niagen will become available in 3,800 Walmart Inc. stores in the U.S. ChromaDex said Tru Niagen is a form of vitamin B3 that helps elevate NAD, to reduce the impact of aging and daily wear and tear on the body. We are grateful to Walmart for their commitment to the Tru Niagen brand and for their collaboration in planning this launch, said Chief Executive Rob Fried. 