21 Important Facts About Vitamin B12 Deficiency
You can eat a ton of veggies and still not get enough vitamin B12. Here are the risks, symptoms, and ways to treat a deficiency.
The energy vitamin
Vitamin B12 is a powerhouse. It helps make DNA, nerve and
blood cells, and is crucial for a healthy brain and immune system. Your
metabolism wouldn't run smoothly without it. But B12 isn't like other vitamins.
It's only found in animal products like eggs, meat, shellfish, and dairy. Up to
15% of people don't get enough B12, and they're more likely to be vegetarians,
have celiac disease or other digestion problems, or be an adult over 50. The
signs of vitamin B12 deficiency include exhaustion, rapid heartbeat, brain fog,
and other symptoms, says Maggie Moon, RD, a Los Angeles–based nutritionist and
owner of Everyday Healthy Eating. Read on to find out more about the causes,
symptoms, and cures for a vitamin B12 deficiency.
Vegetarians and vegans are at risk
Vitamin B12 occurs naturally in animal products. So if your
diet largely consists of plant-based foods such as fruits, veggies, beans, and
soy, you're at risk for deficiency. "Vegetarians who consume eggs and
dairy should aim to include at least one source a day from both of these food
groups," says Stephanie Middleberg, R.D., nutritionist at Middleberg
Nutrition in New York City. Vegans—who by definition consume no animal
products—need to take a supplement or consume vitamin B12–fortified foods, such
as breakfast cereal and grains. Other foods fortified with B12 include nondairy
milks and meat substitutes, but not all are, so check the label first to make
sure.
Adults over 50 are also at risk
As you age, the stomach produces less acid, and stomach acid
is key for B12 absorption, says Middleberg. About one in 31 adults over 50 are
deficient, estimates the Centers for Disease Control and Prevention.
"Older individuals also often have poorer appetites and food intakes, and
they may be on medications (such as heartburn meds) that can further reduce
stomach acid levels," she says. In fact, some seniors actually lose the
ability to absorb vitamin B12 from food at all, and must get it via supplements
or, if the deficiency is severe, injections.
Early symptoms include weakness and fatigue
B12 isn't nicknamed the energy vitamin for nothing.
Inadequate B12 intake makes a dent in red blood cell production, and some of
the earliest signs of a deficiency include feeling dragged, confused, and weak.
Problem is, says Middleberg, these clues are so vague, and not everyone
experiences them the same way. And since they can be attributed to so many
other possible triggers, most people don't think to be tested. If these
symptoms hit and stick around for weeks, it's best to consult your doctor and
rule out other causes, she says. Similar tip-offs include dizziness, impaired
thinking, and confusion.
Heartburn drugs can cause it
Some prescription heartburn drugs suppress the production of
stomach acid, which is needed to absorb vitamin B12. A 2013 study from the
Journal of the American Medical Association backs this up. Researchers found
that taking meds called proton pump inhibitors (like Prilosec and Nexium) for
more than two years was linked to a 65% higher risk of vitamin B12 deficiency.
And two years or more using H2 receptor blocker drugs (such as Pepcid and
Zantac) is associated with a 25% boost in deficiency odds. If you take these
regularly, talk to your doctor about steps you can take to protect yourself.
It can be mistaken for dementia
"Symptoms of a deficiency often mimic those of
dementia, such as memory loss, disorientation, and difficulty thinking and
reasoning," says Middleberg. It can be hard distinguishing deficiency from
dementia, especially since older folks are at risk for both. And the two
conditions often overlap; 75% to 90% of B12 deficient people also have
neurological complications such as dementia, says Moon. But even when a B12
shortage strikes younger people, it still typically resembles dementia. Experts
aren't exactly sure of the relationship between the two, but patients with
unexplained cognitive decline should be tested for B12 deficiency, suggests
Moon.
Taking birth control pills sets you up for it
"Women who have been on oral contraceptives for
extended periods of time tend to have issues absorbing vitamin B12," says
Middleberg. "Studies show that pills that are higher in estrogen are more
strongly associated with B12 and folate (folic acid, or vitamin B6) deficiencies,
leading to the assumption that the estrogen in the pill is the reason for this
impaired absorption." If you're on the pill, talk to your doctor about the
risks, and if you should take B12 supplements as a backup.
The best sources are meat and fish
Beef liver and clams are tops in B12, according to the
National Institutes of Health. If you're not a fan of either, plenty of good
options abound. Beef, turkey, oysters, chicken, trout, and salmon are B12
superstars; a serving of each delivers close to or more than 100% of your RDA
(2.4 mcg for men and women over 14, going up to 2.6 and 2.8 for pregnant and
breastfeeding women respectively, says Moon). Eggs (0.6 mcg per egg, 10% of
daily value) and milk (1.2 mcg per cup of low-fat, 18% of daily value) are also
solid sources.
Fortified foods and supplements can help
Both can help vegans, vegetarians, and older adults and
others who are unable to absorb naturally occurring B12, says Moon. When
absorption is an issue, "simply loading up on foods naturally high in B12
may not solve the problem," she says. "The synthetic form of B12 is
more readily absorbed." Best places to find it in food: fortified cereals,
many of which have 100% of your RDA.
Heavy drinking increases your odds
More than a few drinks on average each day can cause
gastritis, or irritation of the stomach lining, and this can lead to low
stomach acid and reduced B12 absorption, says Middleberg. Alcohol plays a role
in deficiency in another way too. B12 is stored in the liver, and alcohol
consumption can impair liver function and deplete B12 stores or make it harder
for the liver to use it.
It can trigger a false positive on a Pap test
Vitamin B12 deficiency even affects the Pap test you get at
your regular gyno checkup to screen for cervical cancer. Low B12 levels can
change the way some cervical cells look, potentially triggering a false
positive, according to the National Institutes of Health. Yet another reason to
shore up your intake of the nutrient.
It's linked to pernicious anemia
There's a specific type of anemia that's triggered by a B12
deficiency. Called pernicious (which means "dangerous," because it
was potentially life-threatening in the past) anemia, it is a red blood cell
deficiency that happens when the stomach doesn't make enough of a protein
called intrinsic factor, which helps the intestine absorb B12, says Moon.
Pernicious anemia can be the result of an autoimmune issue, a problem with the
stomach lining, or even a congenital condition passed down through families.
Treatment usually involves B12 shots, possibly combined with supplements.
It can be hard to recognize a deficiency
"Because the body can store B12 for three to five
years, early symptoms of a deficiency usually appear gradually, so you're
unlikely to notice them," says Middleberg. After initial clues like
fatigue, weakness, and brain fog set in, says Middleberg, more advanced
tip-offs show up, such as numbness and tingling of the limbs, depression, and
paranoia, even hallucinations. The signs are so varied and they don't strike
everyone, so it's tough to diagnose even at a later stage. "Which symptoms
hit when depends also on what caused the deficiency—malabsorption, which could
mean they are absorbing some B12 and the deficiency is occurring more slowly,
or total lack of animal products, which would likely cause the deficiency to
develop more quickly," says Middleberg.
A blood test is the only way to confirm it
The CDC defines vitamin B12 deficiency as blood levels below
200 pg/mL (picograms/milliliter), says Moon. "Blood tests are generally
accurate, but a false positive is possible related to certain cancers, oral
contraceptives, folate (folic acid) deficiency, and pregnancy," she says.
"False negatives are also possible, as sometimes seen in people with liver
disease, poorly functioning kidneys, or certain blood cell disorders."
Your GP or primary care physician can take care of testing you.
It's linked to immune system issues
"B12 plays an important role in white blood cell
production, and white blood cells are essential for proper immune system
functioning," says Middleberg. Not only can a lack of B12 lower your
immunity, some immune system disorders can increase your likelihood of becoming
deficient. Grave's disease, for example, an autoimmune condition of the thyroid
causing hyperthyroidism, is a risk factor for developing pernicious anemia,
which in turn leads to B12 deficiency.
Digestive problems can cause it
People who deal with GI issues are at a higher risk of a B12
shortage because digestive problems can make absorbing the nutrient more
difficult, says Middleberg. "Those with gut issues, such as colitis,
Crohn's disease, inflammatory bowel disease, and leaky gut syndrome are at a
higher risk," she says. Celiac disease sufferers can also have problems
with absorption. If you have any of these, talk to your doctor about
supplements or B12 shots, since all the B12-rich food in the world won't help
your body shore up its reserves if it can't be absorbed by the GI tract.
It can happen after weight loss surgery
"Some surgeries that affect the GI tract, like gastric
bypass surgery, make it hard to absorb B12," says Moon. One reason has to
do with the decrease in the body's ability to digest food; it's also caused by
iffy levels of intrinsic factor, a protein that helps the body absorb B12. The
absorption problem could be a permanent one, and people who undergo gastric
bypass may need to take vitamin B12 supplements for the rest of their life or
risk a shortage.
It can cause tingling, weakness, and balance issues
Depletion of your vitamin B12 stores leads to nerve damage.
No wonder pins and needles in your hands and feet, shaky body movements, and
trouble walking are all consequences of long-term B12 deficiency, says
Middleberg. Like so many other B12 deficiency signs, these can be attributed to
other causes, including old age. The only way to know for sure is to see your
doctor for a test.
Babies can get it too
In infants, vitamin B12 deficiency is serious—it can lead to
symptoms such as anemia, problems with movement, difficulty reaching
developmental milestones, and failure to thrive, which may be fatal. Low B12
levels are rare in infants but it can happen if a baby is fed a strict diet
free of any animal products or if a breastfeeding mom is a vegan who doesn't
take vitamin B12 supplements (and breast milk is the only source of nutrition.)
B12 supplementation can reverse the course, one study from the journal
Pediatrics shows, and taking prenatal vitamins fortified with B12 in pregnancy
can help prevent it.
Visible signs include pale skin, a sore tongue, and mouth ulcers
Paleness; mouth sores; a red, swollen, beefy tongue—these
are some of the visible signs of a B12 shortage. Caused by deficiency-related
changes in blood flow, these signs can show up years after the depletion sets
in, says Middleberg. A rapid heartbeat or heart palpitations is another blood
flow-related sign, and sometimes bruising easily is also a result of a
longstanding deficiency. But these seemingly unrelated signs don't show in all
B12 deficient people, or they come on so slowly, it's hard to notice them, says
Middleberg.
It might cause permanent damage
Vitamin B12 deficiency that persists for years can cause
severe, irreversible neurologic damage—think memory loss, disorientation, and
an inability to concentrate. Other permanent side effects include nerve damage,
insomnia, erectile dysfunction, even difficulty with bowel and bladder control,
says Moon. The upside: "Many symptoms can be reversed if caught early and
treated with B12," she adds.
It's hard to overdo vitamin B12
Unlike fat-soluble vitamins that accumulate in your body and
can have side effects in excess, B12 is a water-soluble vitamin, meaning your
body only absorbs a small amount and the rest is excreted through urine, says
Middleberg, Good news if you need to refill your stores of this nutrient, but
worry about taking too much. But keep in mind that large amounts of B12 at one
time may cause diarrhea and all-over itchiness, she adds. If your doctor
recommends supplements, read the label and take only the amount recommended by
your M.D.
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