Vitamin D levels in fish and shellfish determined by liquid chromatography with ultraviolet detection and mass spectrometry

► Amounts of vitamin D3 were determined in fish and shellfish by UV and MS detection. ► Calibration curve results were indistinguishable from those by response factors. ► Response factors allowed quantification at lower levels than calibration curves. ► The reported method was validated using NIST reference material SRM 1849. ► Results were lower for mollusks and shrimp than other extant values.