Cocoa beans are susceptible to fungal contamination and often contain substantial amounts of ergosterol, the precursor to vitamin D2. We hypothesized that sun-drying the fermented cocoa beans might lead to the conversion of ergosterol to vitamin D2. We quantified vitamin D in cocoa and cocoa-based foods by liquid chromatography-tandem mass spectrometry. Here, we show that cocoa beans from different growing regions contain vitamin D2. Particularly high vitamin D2 content was found in cocoa powder and butter. Among the chocolates, dark chocolate had the highest vitamin D2 content (ranging from 1.90 to 5.48 µg/100 g), white chocolate had the lowest vitamin D2 content (ranging from 0.19 to 1.91 µg/100 g), and chocolate nut spreads had a comparatively low vitamin D2 content, with an average of 0.15 µg/100 g. Thus, cocoa and chocolate are clearly a dietary source of vitamin D, therefore, it is necessary to update food composition databases.