B12 deficiency - in data

[Guest guest]

B12 deficiency - in data

http://www.latimes.com/features/health/la-he-

closer14jan14,1,7604653.story?coll=la-headlines-health

Physicians say the well-nourished rank-and-file don't need extra

Vitamin B12, but that hasn't dulled its luster among those who say

it boosts energy.

By Janet Cromley, Los Angeles Times Staff Writer

New York Yankees pitcher Clemens is feeling the heat. A former

trainer has said he injected the seven-time Cy Young winner with

steroids and human growth hormone, but Clemens says the only

injections he received were of vitamin B12 and lidocaine, an

analgesic. Lidocaine is sometimes injected into joints to dull joint

pain -- a potential problem for an aging athlete -- but B12

injections are more commonly used to treat pernicious anemia and

address diet deficiencies in the elderly. Physicians generally

believe that the well-nourished rank-and-file don't need it, but the

vitamin hasn't lost its luster among those who say it boosts energy.

Vitamin B12 is an essential vitamin found primarily in animal foods.

The body uses it in the formation of DNA and red blood cells, and

it's necessary for the healthy functioning of the nervous system.

For people who are deficient or at risk of deficiency, injections

can be helpful. For a well-nourished pitcher hoping to improve his

fastball, not so much.

" Some athletes believe that vitamin B12 injections will increase

oxygen [supply to the muscles] and that that enhances performance, "

says Giancoli, a spokeswoman for the American Dietetic Assn.

and consultant for the L.A. Unified School District on nutrition and

policy. " But in the absence of a vitamin B12 deficiency, the studies

don't support that. "

Aside from a 1989 report in the International Journal for Vitamin

and Nutrition Research, which found that a combination of B1

(thiamin), B6 (pyridoxine) and B12 (cyanocobalamin) improved fine

motor skill in target shooting, the evidence is scant, writes

Brenna, professor of human nutrition at Cornell University, in an e-

mail.

And B12 injections are not going to give the average person an

energy boost, says Dr. Baron, chief of staff at Santa -

UCLA Medical Center and Orthopaedic Hospital.

" For my entire career, I have encountered patients who have

requested B12 shots, and I've been explaining to them that they

serve no useful purpose, " Baron says. " Honestly, this is an argument

that's been going on between Western scientific physicians and

complementary and alternative healthcare providers for many, many

years. "

Some weight-loss programs even recommend B12 injections, says

Hill, director of the human nutrition center at the University of

Colorado. " But there's no indication that they're doing any good, "

he says.

In fact, when the body is drenched with B12, the kidneys will filter

out whatever isn't needed, says Dr. Karp, an internist and

assistant professor of clinical medicine at USC School of Medicine.

The upside is that too much B12 probably won't hurt you, he says.

The basis for the belief that vitamin B12 shots can provide energy

goes back decades, Baron says. " Before we knew how to manufacture

B12 in an injectable form, people who were deficient for various

reasons were quite ill, " he says. Once physicians began giving B12

shots to this population, " people who were horribly chronically

anemic from B12 deficiency just basically came to life, " he

says. " It was a miracle. "

The average person needs 2.4 micrograms of B12 per day, and most

people get sufficient amounts in their food, particularly given how

many foods -- such as cereals, nondairy milk, meat substitutes and

protein bars -- are now fortified with B12, Giancoli says.

Vitamin B12 has a somewhat tangled path to absorption. The vitamin

needs an acidic environment in the stomach in order to be released

from food. It then binds with a glyco-protein compound called

intrinsic factor, which allows it to be absorbed through the small

intestine. If the stomach doesn't have a sufficient hydrochloric

acid or lacks intrinsic factor, absorption will be limited.

To be sure, a deficiency of B12 can have serious consequences --

including pernicious anemia and nerve damage. " The nerve damage can

start with memory problems, declined cognitive function, tingling in

the extremities and can progress, " Giancoli says. " And the

neurological changes may not be apparent in everyone. There may be

very general symptoms, like fatigue, weakness, weight loss,

constipation, loss of appetite. "

People most at risk for B12 deficiency are patients with certain

types of gastrointestinal disorders (such as Crohn's disease),

vegans and the elderly. The elderly are at risk for a number of

reasons, says Dr. Marie Bernard, a spokeswoman for the American

Geriatrics Society.

" As you get older, you're more likely to have accumulated medical

problems that might prevent you from absorbing B12 optimally, "

Bernard says. Those events would include surgery to remove part of

the intestine, and use of certain medications, such as acid-

suppressing drugs.

As for that other segment clamoring for injections -- the worried

well who believe the shots boost energy -- B12 may also have a

benefit of sorts: a nice little placebo effect.

" Quite frankly, " Karp says, " I'll sometimes get a new patient who

says that they're getting a monthly vitamin B12 injection and that

it makes them feel better, so I'll continue to give it to them. If

it makes them feel better, that's still something. "