Elements Found in Vitamin B12

Also known as cobalamin, vitamin B12 is one of the critical nutrients for red blood cell production in your body. It also plays important roles in the normal function of your nervous system. The richest dietary sources of B12 are animal in origin, such as meat, eggs and dairy products. A number of chemical elements make up vitamin B12, including carbon, hydrogen, nitrogen, oxygen, phosphorus and cobalt.


Carbon and Hydrogen

Carbon and hydrogen lead the pack as two of the most common elements in any vitamin -- or any molecule of life, for that matter. Together, they form the skeleton of the molecules of life, according to biochemists Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.. Most of the carbon and hydrogen atoms in B12's structure are not chemically reactive, but simply support the other atoms like a scaffolding.

Nitrogen and Oxygen

Nitrogen and oxygen are also quite common in the molecules of life and appear in vitamin B12's chemical structure. They link with carbon and hydrogen atoms to form the ring structure that makes up the B12 molecule. The resulting shape of the B12 molecule is similar to that of chlorophyll and heme, the substances that make plant leaves green and blood cells red, respectively. Like carbon and hydrogen, nitrogen and oxygen tend to be much more reactive in nature than in the B12 structure.


Phosphorus is less common in nature than carbon, hydrogen, nitrogen and oxygen. However, it's an important building block of deoxyribonucleic acid --simply known as DNA-the carrier molecule of your genetic material. While B12 contains many carbon, hydrogen, nitrogen and oxygen atoms, there's only one phosphorus atom. In vitamin B12, phosphorus occurs in the form of the generally very reactive phosphate group, whose chemical structure is PO4.


The most unusual structural element in B12 is cobalt, a metal that's critical for the vitamin's normal function. A single cobalt atom sits right at the center of the molecular structure of each B12 unit and is held held in place by several constituent nitrogen atoms. Again, this is reminiscent of the chlorophyll molecule, which has a magnesium at the center of its ring structure. In the heme molecule, an iron atom holds a similar central position as cobalt, surrounded by a ring structure.

  • Biochemistry; Mary Campbell, Ph.D. and Shawn Farrell, Ph.D.; 2005
  • Biochemistry; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007

Photo Credits:

  • hen's eggs and quail's eggs image by Maria Brzostowska from Fotolia.com

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.