Studies have found that 20% of Americans ages 65 and over have low levels of the vitamin in their blood... More serious shortages can result in dementia or anemia, because B12 is essential for the production of red blood cells in the bone marrow. Breast-fed infants of mothers with a B12 deficiency are at risk for severe developmental abnormalities and irreversible neurological damage. Some experts say that it’s the most common nutritional deficiency in the developing world and possibly in the United States as well.
...the crystalline form of the vitamin contained in pills and breakfast cereals is more readily absorbed than the “natural” form found in food... Plants neither use nor contain vitamin B12, so the only dietary sources are animal-derived: meat, fish, shellfish, poultry, eggs, milk, and milk products. Beef liver and several varieties of fish contain high amounts, dairy products and eggs not so much. Vegetarians can eat tempeh, which is made from fermented soybeans (the bacteria produce B12).
In normal digestion, stomach juices pry B12 loose from animal protein. But the small intestine can’t absorb the vitamin in this liberated, solo state. To be absorbed, it must be combined with a protein called intrinsic factor that is produced by cells in the lining of the stomach.
Four ways deficiencies develop
1. Diets without food derived from animals. (Explained above.)
2. Lack of stomach acid. Up to 30% of people ages 50 and over suffer from atrophic gastritis, a thinning of the stomach lining. This condition reduces the acid secretions that free B12 from animal protein, so much less is absorbed by the small intestine.
3. Lack of intrinsic factor. Some people’s stomachs don’t make enough intrinsic factor, so they can’t absorb enough B12.
4. Gastrointestinal disorders and surgeries. Crohn’s disease might cause a B12 shortage because it interferes with the functioning of the small intestine. Some people develop a B12 shortage after a surgical procedure that shrinks the stomach, such as gastric bypass, because a smaller stomach means far fewer of the cells secreting stomach acid and intrinsic factor.
I sure am glad I take my multi-vitamins!
Source: Harvard Health Letter, Volume 30, No. 10 - "Are You Getting Enough of This Vitamin?"
7 comments:
Thats interesting that people who have gastric bypass surgery may be at risk for b12 deficiency. I know a few close people that have had this and it would be a good thing to let them know of.
Oh no! I'm over 50 (barely) which means my stomach lining is getting thinner! Thanks for the heads up though. Keep on blogging! GO JACKS!
Hey Masha, you said that one of the four ways deficiencies develop is because Diets without food derived from animals. Are Vegetarians at a higher risk or what would a solution be for them?
Its really interesting that so many people neglect, or just don't know about this vitamin how beneficial it really is! Gotta take that multi vitamin to get the amount of B12 you need!
This is a great add for vegetarians that don't take their multivitamins. It is incentive to start. B12 is important! It is good to know that it is just as beneficial in a supplement form.
In response to your last post and Libby's response, I too find it interesting that some people just don't have the ability to absorb vitamin B12 as well as others, for whatever reason. I know someone whom has had the gastric bypass surgury, I actually work with her, and one day at work I saw her with a box of tons of pills/vitamins and I asked her why she took so many and she told me she had had the procedure and was to take several of these pills each day for the rest of her life. I was kind of amazed. I know people have to take pills for certain things but to have to do it everyday for the rest of your life? I had no idea that gastric bypass surgury meant you'd have to suppliment with so many nutrients and vitamins. It's interesting that even people who have not had that operation have trouble absorbing their vitamins as well.
Excellent blog, it really looks nice and you know your stuff!
thanks for posting the chemical formula for B12 i've always thought it was mindblowing how complex it is,
and compared with the other vitamins, which are for the most part simple carbon rings.
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