Vitamin B-12 and folic acid deficiencies

[Astronuc]

According to a program I heard yesterday, roughly 16% of Americans are deficient in Vitamin B₁₂. There was also a related concern about deficiencies of folic acid, B₆. The two are somehow related.

You can take all the vitamin B-12 you want...if your body can’t absorb it, it’s not doing you a bit of good. And B-12 is a vitamin that does a lot of good.

Ref: The Health Show #1263

There has been concern about the interaction between vitamin B₁₂ and folic acid. The National Institutes of Health has found that "Large amounts of folic acid can mask the damaging effects of vitamin B₁₂ deficiency by correcting the megaloblastic anemia caused by vitamin B₁₂ deficiency without correcting the neurological damage that also occurs", there are also indications that "high serum folate levels not only might mask vitamin B₁₂ deficiency but could also exacerbate the anemia and worsen the cognitive symptoms associated with vitamin B₁₂ deficiency".

http://en.wikipedia.org/wiki/Folic_acid#B12_deficiency

Vitamin B12, aka cobalamin, http://en.wikipedia.org/wiki/Vitamin_B12

It is important to determine if there is a deficiency and if that deficiency is related to the inability to absorb B₆ or B₁₂, which is indicative of other, potentially treatable, issues related to the digestive system. I may know at least one, possibly two people, who may have experienced B₁₂ deficiency.

 

[Monique]

According to a program I heard yesterday, roughly 16% of Americans are deficient in Vitamin B₁₂.

What is the demographics of that group, would that mostly be the elderly or people taking anti-acid medication?

 

[Monique]

I think the radio show is referring to the study described here: http://www.ars.usda.gov/is/pr/2000/000802.htm

Apparently the malabsorption occurred at the same incidence in young and old (surprising) and that the underlying cause is not well understood:

We saw a high prevalence of low B12 even among the youngest group,” Tucker said. [..] Oddly, the researchers found no association between plasma B12 levels and meat, poultry, and fish intake, even though these foods supply the bulk of B12 in the diet. “It’s not because people aren’t eating enough meat,” Tucker said. “The vitamin isn’t getting absorbed.”

In the elderly, it’s probably because they don’t secrete enough stomach acid to separate the vitamin from the meat proteins that tightly bind it. But Tucker can only speculate about the reasons for poor absorption of the vitamin from meat among younger adults or why B12 appears to be better absorbed from dairy products than from meats.

 

[mazinse]

vit b12 is in meat, vegetarians suffer from this def, but they can get supplement from certain bacteria.

 

[Monique]

Sigh.. vitamin B12 is in more places than meat. Vegetarians only have a slight increased risk for B12 deficiency, vegans do have a high risk.

My quote says: "“It’s not because people aren’t eating enough meat,” Tucker said. “The vitamin isn’t getting absorbed.”"

According to the OP 16% of Americans have a vitamin B12 deficiency, however: only ±0.5% of Americans are vegan.

 

[Aidyan]

Sigh.. vitamin B12 is in more places than meat. Vegetarians only have a slight increased risk for B12 deficiency, vegans do have a high risk.

Only those vegans who do not supplement it. Those who do have no more no less risk than anyone else. I'm vegan four years now and blood tests show that values are nominal. I know of several who are vegan longer and have no deficiencies too. I think the risk of B12 deficiency in vegans has been greatly exaggerated.

 

[feihong47]

It is rare to see B12 deficiency solely due to decreased intake from foods. Most of the times, surgical patients who are surgically devoid of a stomach or terminal ileum (due to tumors, or other disorders) can be deficient in B12 due to the inability to absorb or produce intrinsic factor that help with absorption. Many gastric bypass patients need ample supplementation due to this. Intramuscular injections are available for those who truly cannot absorb them.