In 1926, Harvard physicians discovered that eating half a pound of liver daily would prevent Pernicious Anemia. The hunt was on to identify the compound in liver that was responsible. In 1947, Karl Folkers (a scientist at Merck) isolated the tiny red crystals of vitamin B12. 'Extrinsic Factor' now had a name.
It was first noticed in 1929 that giving beef alone to Pernicious Anemia patients did not improve the anemia, but when given with human gastric juice, it did. Giving gastric juice alone (without beef) didn't help either. In 1936, the scientist, W.B Castle called the substance in beef 'Extrinsic Factor' and the substance in gastric juice 'Intrinsic Factor'. They only work when given together. Today we know Extrinsic Factor by a different name, vitamin B12.
Gene expression can be regulated without changing the DNA sequence through what is called an 'epigenetic mechanism' that frequently involves 'methylation'. The attachment of a methyl group (-CH3) to one of the DNA building blocks (cytosine) stops the gene being read. These methyl groups come from choline, betaine, folate and vitamin B12.
The word 'pernicious' means 'a harmful effect, especially in a gradual way'. This is the name given to an anemia characterized by larger, more immature red blood cells that is caused by vitamin B12 deficiency. It takes a long time to develop because it can take years to deplete the body stores of this vitamin in the liver.
The integrity of the cell is protected by a membrane barrier that is selective for what it allows in or keeps out. Embedded in the cell membrane are specialized proteins that recognize very specific molecules to transport into or out of the cell. Vitamin B12 is absorbed through one of these specialized receptors.
B12 is the largest and most complex vitamin and that makes it vulnerable to be damaged by digestive enzymes. Two proteins are specially designed to protect B12 in the GI tract. Haptocorrin protects B12 in the stomach and Intrinsic Factor (IF) protects it on its long journey down the small intestine to the B12 receptors for absorption.
The Vitamin B Team. B12 (cobalamin) B9 (Folate) B6 (pyridoxine) and choline are interconnected in what is called 'transmethylation metabolism'. Foods containing these essential nutrients make 'methyl groups' or single carbon units (-CH3) available for use in the methionine pathway - critical to DNA expression.
Folate was first isolated from spinach in 1941 and the scientists who purified this new vitamin decided to name it folic acid, from the Latin word for leaf, 'folium'. In 1943, other groups of researchers made the synthetic form which is now referred to as folic acid, which gets converted to the active folate in the body. Both are also known as Vitamin B9.
Folate and folic acid are not the same. Folate is what is found in nature and mainly in leafy vegetables. Folic acid is synthesized and is the form used in most supplements and for food fortification. It gets converted into folate in the body where it is active in many important biologic functions.
B12 is 3 times bigger than the next biggest vitamin (vit K) and 11 times bigger than the smallest (nicotinic acid or B3). It took an international collaboration of 19 countries, 103 scientists (from Harvard and the Swiss Institute of Technology) 12 years to synthesize it in 62 chemical steps. It is the most complex vitamin by far - it must be important.