Millions of Americans suffer tingling, numbness or pain in their hands or feet...dizziness...balance problems... depression...and/or memory loss because they are deficient in vitamin 13-12, a nutrient that most of us—including many doctors—rarely think about. Low levels of vitamin B-12 can even raise the risk for heart disease and osteoporosis, according to research.

Good news: You can avoid the potentially serious complications of vitamin B-12 deficiency with simple, inexpensive treatment—if the problem is identified soon enough. Permanent damage can occur if the deficiency is not treated within a year of the development of symptoms.

What you need to know…

A Key To Proper Nerve Function

Vitamin B-12 is needed to maintain the layers of tissue, called the myelin sheath, that insulate each nerve cell. We need only a very tiny amount of the vitamin each day-2.4 micrograms (mcg).

The vitamin is abundant in meats (such as red meat, poultry and liver), shellfish, eggs and dairy products. Because vitamin B-12 is readily stored by the body (mainly in the liver), doctors have long assumed that deficiency is rare.

But a complex process must occur before vitamin B-12 can do its job. When it is consumed, the vitamin must be split from the proteins to which it is attached, carried into the small intestine and transported throughout the body with the help of other proteins.

If there is a problem—for example, a person takes a drug that interferes with vitamin 0-12 absorption—a potentially dangerous deficiency can result. Among adults over age 65, up to 25% have been found in studies to have a clear B-12 deficiency (blood levels of less than 225).

The Toll Of B-12 Deficiency

Many so-called symptoms of aging—both physical and mental—actually could be the result of B-12 deficiency. When a lack of this vitamin impairs the nervous system, a variety of problems can result, including weakness, dizziness and tremor—all of which can be mistaken for signs of neurological disorders, such as Parkinson's disease, multiple sclerosis, vertigo or neuropathy (nerve damage that causes pain or numbness).

A B-12 deficiency also can affect how you think, feel and act, resulting in irritability, apathy, confusion, forgetfulness—even serious depression, dementia, paranoia and/or hallucinations. Vitamin B-12 deficiency can lead to symptoms that are sometimes mistaken for Alzheimer's disease.

The cardiovascular system also can be affected. Vitamin 11-12—along with vitamin 0-6 and folic acid (another B vitamin)—plays a key role in the breakdown of homocysteine, a naturally occurring amino acid. Elevated levels of homocysteine damage blood vessels and promote the buildup of fatty deposits in the arteries (atherosclerosis) as well as abnormal blood clot-ting. Several studies have linked high blood levels of homocysteine to significantly increased risk for heart disease, heart attack, stroke and blood clots in the lungs and/or extremities.

The dangers of elevated homocysteine are widely known, but many doctors—cardiologists among them—simply prescribe high doses of folic add to lower levels of the amino acid. ignoring the need to test for and possibly correct vitamin 13-12 deficiency as well.

Also linked to B-12 deficiency…

  • Breast cancer. A Johns Hopkins study of 390 women found that those with the lowest levels of 11-12 were two to four times more likely to develop breast cancer than those with healthier levels.
  • Infections. In another study. 30 older adults who had very low levels of B-12 produced fewer antibodies when vaccinated against pneumo-nia—leaving them with less protection against this potentially fatal infection than adults with adequate levels of B-12.
  • Osteoporosis. Research shows that 13-12 deficiency is linked to osteoporosis—in part, because 13-12 is crucial to the function of osteo-blasts (bone-forming cells).

Are You At Risk?

Aging is a primary risk factor for 8-12 defi-ciency. That's because 30% to 40% of people over age 50 suffer from atrophic gastritis, which damages the stomach lining, markedly reducing production of the stomach acid needed to absorb vitamin B-12. Many older adults also fail to eat vitamin B-12-rich foods.

Another cause of B-12 deficiency is pernicious anemia—an autoimmune disorder in which the body does not produce a substance called intrinsic factor, which is necessary for the vitamin's absorption. Pernicious anemia is more common among people who have other auto-immune diseases, such as rheumatoid arthritis, lupus, thyroid disease and type 1 diabetes.

It's now recognized that Crohn's disease (chronic inflammation of the intestinal wall) and celiac disease (intolerance to gluten, a protein found in wheat, barley and rye) can impede absorption of vitamin 8-12. So can gastrointestinal surgery—particularly gastric bypass.

In addition, commonly used medications—such as the heartburn drugs known as proton pump inhibitors, including omeprazole (Prilosec) and lansgmarole (Prevacid)...and H2 blockers, including ranitidine (Zantac) and famotidine (Pepcid) well as the oral diabetes drug metformin (Glucophage, Gluowance)—can interfere with B-12 absorption.

Because vitamin B-12 is found only in animal products, strict vegetarians are at high risk for a deficiency. Some research shows that 80% of people who do not eat animal products and fail to take a 13-12 supplement have a deficiency of the vitamin.

Get The Right Test

When doctors order a complete blood count (CBC), among the abnormalities they look for is macrocytic anemia, a condition in which red blood cells are abnormally large. This can be a sign of vitamin 13-12 deficiency. But in people who take supplements that contain folic acid—as do most multivitamins—blood test results may appear normal even when there is a vitamin B-12 deficiency. (Folic acid can "mask" such a deficiency.) A blood test that specifically measures 13-12 levels also is available. However, this test is not always accurate—it has a wide "normal" range and can be inconsistent in its sensitivity.

The most sensitive B-12 test measures the amount of methylmalonic acid (MMA) in the urine. Because vitamin B-12 plays a key role in the production of MMA, results of this test can conclusively diagnose or rule out B-12 deficiency. Health insurance will pay for the test if the patient has symptoms of B-12 deficiency or is at high risk for deficiency.

Best Treatment Options

If you have a 13-12 deficiency. injections of 1,000 mcg—daily at first, then weekly, then monthly—are the most dependable solution, especially if neurologic symptoms are present. Sublingual (under-the-tongue) doses may be an alternative for some people. Ask your doctor. The MMA test should be repeated in three months to check the sublingual supplement's effectiveness.

If you have a B-12 deficiency, it's also wise to receive a homocysteine blood test before treat-ment to determine whether inadequate B-12 has raised your homocysteine levels, thus increasing your risk for vascular disease.

Slow Memory Loss with Milk!

Elderly patients with low levels of vitamin B-12 have twice as much brain shrinkage as those with higher levels. Drinking two glasses of milk (even skim) daily is enough to increase vitamin B-12 to normal levels, which could help slow cognitive decline.

Also: Take up to 500 micrograms each day of B-12 supplements.

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