Are You Low on
Vitamin B12?
From:
Natural Solutions
Q: I’ve been a vegan for nearly 25 years and was
recently diagnosed with low vitamin B12 levels. I’m being treated
with B12 shots, but how can I prevent getting deficient
again?
A: Vitamin B12 deficiency is a growing health
problem, caused in whole or in part by vegetarian diets, antacids,
diabetes medications, alcoholism, iron deficiency, aging, and
digestive disorders (such as malabsorption, Crohn’s disease, and
celiac disease). Recent research indicates that nearly 40 percent
of adults have marginal levels of this vital nutrient and are at
risk for deficiency symptoms.
Your body needs B12 to produce blood cells, replicate DNA, and form
the protective sheath around nerves. Inadequate amounts of this
nutrient can cause anemia and nerve damage—which manifest as memory
problems, fatigue, poor concentration, depression, and numbness or
tingling in the feet or hands. Such symptoms may take as long as 18
months to reverse and, indeed, may never resolve. Of more concern,
perhaps, is that the risk of dementia, which already affects more
than a third of octogenarians, doubles with suboptimal B12
levels.
Since only animal products (including dairy and eggs) appear to
contain biologically active vitamin B12, your vegan diet most
likely caused the deficiency. I recommend continuing to supplement
with B12 in the future. Fortunately, recent research has found that
oral supplementation with high-dose vitamin B12 (1,000 mcg a day or
more while correcting a deficiency) restores normal levels just as
effectively as injections. While blood levels usually normalize
within one to two weeks, it 
takes six months or longer to
replenish whole-body stores. Check with your doctor to see if
getting your B12 through pill supplements rather than shots would
work for you.
Although you only need 2 to 3 mcg of B12 daily, your body sometimes
absorbs only 1 percent of B12 supplements. I recommend at least 500
mcg a day to ensure adequate levels. For example, vegetarians who
consume three servings of dairy products a day (providing the
requisite 3 mcg of B12) theoretically get enough of this nutrient.
In practice, however, they’re often low because it’s not all
absorbed. So have your levels checked or take supplements. Even
nonvegetarians who forgo multivitamins and don’t regularly eat
fortified cereal or dairy products are at risk for deficiency; they
should get evaluated as well. Spirulina and a few other seaweeds
offer plant sources of B12, but debate rages about whether it’s
biologically active in the body. In fact, some research suggests
these inactive forms of B12 may actually lower your levels of the
nutrient.
3 ways to get started:
1. Eat foods high in vitamin B12, such as fortified grains and
cereals (with soy milk, if vegan), meat, dairy, and eggs.
2. If you are vegan, suffer from Crohn’s disease, or have any other
risk factors for B12 deficiency, consider supplementing with 500
mcg a day.
3. If you fall into the high-risk category described by Dr.
Lonsdorf or you notice symptoms of fatigue, poor concentration, and
tingling in the feet or hands, consider having your doctor check
your B12 levels. You may need to restore your levels with higher
dosages of supplements.
~Nancy Lonsdorf, MD
Nancy Lonsdorf, MD, is dean of faculty for Vedic Medicine at
Maharishi College of Vedic Medicine in Fairfield, Iowa. She’s also
the coauthor, with Maharishi Ayurveda, of The Ageless Woman:
Natural Health and Beauty After Forty (MCD Century, 2004).