This LC-MS of Vitamin D website has been established to disseminate information regarding the structure and analysis of Vitamin D by liquid chromatography/ mass spectrometry (LC-MS).

Mass lists from these pages pertain to LC-MS of Vitamin D and its metabolites by atmospheric pressure chemical ionization (APCI)  mass spectrometry and electrospray ionization (ESI) mass spectrometry (MS) techniques:


Data are given for protonated molecules and other adducts of Vitamin D and its metabolites, and related fragment ions.  Accurate isotopic masses are given, not average molecular weights that would be calculated from Periodic Table masses, since isotopic masses are observed by mass spectrometry.

Mass lists are given as:

1.  Structures of Vitamin D and its metabolites.

2.  Structures of fragments from Vitamin D and its metabolites.

3.  Masses of structures of Vitamin D and its metabolites

4.  Masses of fragments from Vitamin D and its metabolites.

The information on LC-MS of Vitamin D was put together by Dr. Byrdwell due to his personal interest in Vitamin D.

The information and mass lists given here are provided as a service to my colleagues.

Please report any errors in these pages to



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Wm. Craig Byrdwell, phd

Resources for Lipid Analysis in the 21st Century

        LC-MS of Vitamin D: These are the two most common molecules in the class of molecules known as “Vitamin D”. The first is Vitamin D3 (Cholecalciferol), which is naturally found in some animals, especially fish and cod liver oil. The second is Vitamin D2 , which is naturally found in certain plants, such as plankton.  Nowadays, many foods are fortified with Vitamin D, including milk, yogurt, breakfast cereals, infant formula, nutritional supplement bars and drinks, and some brands of orange juice, processed cheese, and margarine.

        Vitamin D3 and D2 molecules are essentially biologically inactive, and must be metabolized to their active forms, shown in the ’Vitamin D Structures’ pages. 

        Vitamin D molecules form protonated molecules, [M+H]+, and dehydrated protonated molecules, [M+H-H20]+, by atmospheric pressure chemical ionization mass spectrometry (APCI-MS).

LC-MS of Vitamin D website

To contact me:


Wm. Craig Byrdwell, PhD

Washington, DC 20009



© 2006-2011

The figures and tables on this website are copyrighted in 2006-2011 by William Craig Byrdwell.  If you use these tables please reference

The class of Vitamin D molecules is made up of Vitamin D1 through D5, identified as follows:

¯ Vitamin D1: a combination of Ergocalciferol with Lumisterol, 1:1

¯ Vitamin D2: Ergocalciferol (made from Ergosterol, or pro-Vitamin D2)

¯ Vitamin D3: Cholecalciferol (made from 7-Dehydrocholesterol, or pro-Vitamin D3)

¯ Vitamin D4: 22,23-Dihydroergocalciferol (Vitamin D2 without the 22,23 double bond)

¯ Vitamin D5: Sitocalciferol (made from 7-Dehydrositosterol)


This LC-MS of Vitamin D website presents information related to the analysis of the two primary dietary forms of Vitamin D molecules, Vitamin D2 (Ergocalciferol) and Vitamin D3 (Cholecalciferol) and their metabolites by liquid chromatography coupled with mass spectrometry.


This page is not funded, endorsed, sanctioned or approved by the USDA Agricultural Research Service.  It is put together as a matter of personal interest of the author for the benefit of those interested in liquid chromatography/ mass spectrometry (LC–MS) of Vitamin D.