Vitamin D, including vitamin D2 and D3 (Figure 1), is essential to calcium absorption and bone health. Current studies suggest vitamin D could help prevent a wide range of disorders. Although vitamin D can be synthesized by the human body from exposure to sunlight, fortification in some dietary sources becomes necessary. We describe an easy and comprehensive LC-MS/MS method using a Transcend TLX-1 system powered by Thermo Scientific TurboFlow technology to measure vitamin D levels in infant formula. TurboFlow technology eliminates most traditional sample preparation steps.