Vitamin B12

Vitamin B12 was discovered simultaneously by two research teams, one in the United States and one in England. It was the culmination of an intensive worldwide search for a compound that could effectively treat pernicious anemia.

B12 and Liver

During the 1930s, researchers around the world began trying to isolate the active ingredient in liver that contained its curative properties. The "antipernicious anemia factor" was believed to be a B vitamin. It was even given the name B12 long before it was isolated.

Testing was surprisingly slow. Patients were fed extracts of liver rather than the liver itself, but for some reason researchers could not measure the amount of vitamin B12 these liver extracts contained. They could only guess at the extracts' potency by measuring red blood cell growth in each patient's blood.

Vitamins on display.
Vitamins on display.

For years, Karl Folkers, an American chemist at a prominent pharmaceutical company, had been directing a research team that was working on the problem. In 1948, the group finally came up with a solution. They found they could measure the vitamin indirectly by measuring the growth rate of certain bacteria that needed vitamin B12 to grow. This system speeded the purification process of the vitamin enormously.

The New Vitamin

The new vitamin was a large and complicated molecule roughly four times the size of a penicillin molecule. The molecule was so complex that its structure could only be worked out through the aid of advanced technology. In 1956 English physicist Dorothy Hodgkin (1910-) completed the mapping of B12′s chemical structure by using x-ray crystallography. She received the 1964 Nobel Prize in chemistry for her work. Vitamin B12 was finally synthesized by Robert Burns Woodward (1917-1979) in 1971, after a ten-year effort.

Pernicious Anemia

Pernicious anemia is a blood disorder in which red blood cells fail to develop normally. The steady decline of red blood corpuscles eventually leads to death. The disease was first described completely in 1849 by English physician Thomas Addison (1793-1860). Addison noted the typical symptoms included increasing weakness and pallor of the patient. This was accompanied by obesity (weight gain) rather than weight loss.

Until the 1920s, this pernicious anemia was always fatal. Then two physicians named George Richards Minot (1885-1950) and William Perry Murphy became inspired by George Whipple's (1878-1976) studies. The Whipple studies showed that beef liver could improve the formation of red corpuscles in anemic dogs. To test Whipple's findings, Minot and Perry began feeding their patients large amounts of beef liver. In 1926, the researchers were able to announce that a daily diet of about a half a pound of liver could control the disease. For their work, Minot, Murphy, and Whipple shared the 1934 Nobel Prize in medicine.

The isolation and synthesis of B12 removed pernicious anemia from the list of deadly medical problems. B12 was the last vitamin to be discovered. Work on the vitamin served to round out the remarkable half-century of vitamin research that began in the 1890s with Dutch physician Christiaan Eijkman (1858-1930).

User Contributions:

joanne reid
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Apr 6, 2008 @ 5:17 pm
I recently took Vitamin B-12 shots. daily. I used up almost 3 bottles. In that time I gained 15 lbs. I am also very low in iron, and so have stopped the B-12 and started taking iron supplements and vit. C. I want to know if there is any connection between the B-12 and the weight gain. It is continuing to climb even though I have stopped taking the shots. My food cravings are through the roof!!!
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Oct 23, 2008 @ 8:08 am
I have also been taking vit. b 12 for a blood disorder and my weight is going up and I have been trying to diet with no help. Is it the Vitamins ???
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Jun 4, 2010 @ 12:00 am
I think som e people DO gain weight from b12, since I started taking it I gained about 8 kilos. So i try not to take it every day.
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Sep 29, 2010 @ 10:22 pm
I agree! I was found to be B12 deficient and since taking the shot 3 weeks ago I have gone up 7 lbs! Nothing in my diet has changed except this shot. My doctor tells me it's not related but I know it is. I have weighted the same for the past 10 yrs, suddenly I have this unusual gain weight? I dont think so. B12 can definitely cause weight gain!
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Mar 27, 2011 @ 7:07 am
I am the opposite way round - since starting my b12 injections 3 months ago I have lost 28lbs. I am now due an injection and I have gained 6 lbs in the last two weeks.
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Mar 17, 2012 @ 4:04 am
Same. Literally. I lost 28 lbs as well, and if my b12 shot is put off by a week or more, I plateau or gain. I think, for me it has to do with my lethargy and depression symptoms of PA though. B12 gives me energy
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Jul 14, 2012 @ 1:01 am
I to have lost exactly 28lbs in 3 months. I feel as if my body is falling apart & waisting away. I get tachycardia with PCP's at different times. I also had an ALIF on April 17th to fix a degenerative disc. I had a serious reaction to the thoracic epidural. My body was numb from neck down. The epidural pump was turned off & no drugs were given. For two hours they tested my skin with an ice pack. Still no change 1 hour 45min my back started to hurt I begged for meds. 1Hour 51 min in the PICU "wile I was awake" the epidural literally dropped from my body li a sheet falling from you on a cold night.I felt every little pain of that fresh surgery for about an hour more as they got my heart rate & BP steady. It was 61/51 & 194 at the time I looked back as my heart tore at my cheast. They got a dulotid pump in and I spent the rest of thfouunde time in the ICU. I went home and I still have not healed normally. I have had bowel issues since 2003 had a small bowel resection then from a looped & .
bowel. 17Inches of gangrenous bowel was removed. During dissection
they found multiple areas of inflammation,polyps, abnormal cell growth. Thankfully it w as s sll. Nonmalignant.
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Aug 17, 2012 @ 12:00 am
Newsflash - Vitamin B12 deficiency still is fatal if not diagnosed effectively and treated correctly. In the UK most patients are only 'allowed' one injection every 3 months - which is the worst treatment regime of any developed country. In many cases this is not enough to maintain the patient in good health, yet the medical profession still refuse to acknowledge symptoms are life threatening. B12 deficiency is very common. B12 deficiency is not rare. B12 deficiency needs to be treated with the seriousness it deserves. This article proves that clinicians and scientists in the early 20thC were better informed about this fatal illness than those of the 21st Century.
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Mar 1, 2013 @ 8:08 am
There are many reasons for a B12 deficiency including atrophic gastritis, stomach surgery, reduced stomach acid (elevated pH), pernicious anemia, not consuming meat or dairy (only sources other than consuming microscopic organisms such as yeast in sufficient amounts), and medications that reduce stomach acid pH such as proton pump inhibitors. Without getting too technical, another problem that is found in the setting of atrophic gastritis and PA is elevated gastrin levels and decreased pepsin levels. Pepsin is a key player in the digestion of proteins, especially tryptophan. Tryptophan is what our body uses to make serotonin and other neurotransmitters and niacin to name a few. In a setting of PA and atrophic gastritis it is possible if not likely, that a tryptophan deficiency will develop. This deficiency leads to a serotonin deficiency and an increased craving for carbs. There is a competition for chemicals to cross the blood-brain barrier and carbs 'distract' these other chemicals so that tryptophan's metabolite can cross and be made into serotonin (our feel good chemical). Vitamins and amino acids play roles in numerous functions in the body and a deficiency/distruption can have a cascading effect and effect numerous systems. Talk with your physician about taking a tryptophan supplement.
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Jul 2, 2014 @ 11:11 am
In every other article that I have read it always states that weight loss not weight gain is attributed to B12 deficiency and that you gain weight once taking B12. I was a size 8 UK I am bordering on a 14 uk I was given B12 injections until December 13 and gained weight whilst having B12 have gained more weight since stopping injections. I was wondering if I could have the details from which the article gathered the information in relation to obesity. Thank you

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