Healthful diet, hidden deficiency: are you getting enough [B.sub.12]?

Most North Americans associate serious vitamin deficiencies with third world countries or extreme poverty, not with their own comfortable lifestyles--and certainly not with low-fat, low-cholesterol, high-fiber diets brimming with whole grains, dried legumes, brown rice, rolled oats, fresh fruits and daily helpings of dark green, leafy vegetables.

But such a diet, although high in health-promoting folate, is also low in vitamin [B.sub.12], a substance found naturally only in meat, fish, shellfish, eggs, milk or dairy products. It's tree that our bodies require only a small amount--about 2 micrograms (mcg)--of [B.sub.12] per day. But if you think your body could skip this miniscule intake without consequence, think again.

A [B.sub.12] deficiency can result in symptoms ranging from severe anemia to serious and possibly permanent nerve damage and cognitive impairment. Left untreated, it can cause increasingly abnormal blood cell division, leading to lymph cancer and death. And while most vegans know they're at high risk of [B.sub.12] deficiency unless they take supplements or eat fortified foods, this hidden health risk blindsides many people who least suspect it.

Better with Age?

As we age, our bodies lose some ability to absorb vitamin [B.sub.12] and may cease absorption altogether. Richard Woodman, MD, a hematologist in the department of medicine at the University, of Calgary, Health Sciences Centre in Alberta, estimates that up to 30 percent or people aged 50 and over are affected to some degree. This puts even those with diets high in animal products at increasing risk of deficiency from midlife on. "After 65, about one in 20 North Americans is clinically deficient in vitamin [B.sub.12]," he says, "but borderline deficiencies are probably much higher and affect a significant percentage of older people."

More dangerously, a high-folate, low-[B.sub.12] diet masks fire first clinical signs of [B.sub.12] deficiency and delays diagnosis, allowing progressive nerve damage to continue unabated for as long as 5 years.

Cathy Thornton found this out the hard way. At 54, she and her husband, Jim, 56, attributed their good health and abundant energy to daily exercise and their 29-year vegetarian diet that included dairy products and eggs. But there came a time when Cathy began to feel anything but energetic.

At first, she passed off her constant tiredness, apathy, sleeping problems, clumsiness and increasingly grouchy moodiness to overwork. Or menopause. Or just plain aging. But when she began stumbling and losing her balance, she knew something was seriously wrong. So did her doctor, who sent her for tests for rheumatoid arthritis, multiple sclerosis, lupus and cancer of the spine. All results were negative.

The mystery was finally cracked by a routine blood test. Cathy's hemoglobin (the oxygen-carrying capacity of red blood cells) was abnormally low, depriving her muscles, brain and organs of the energy they needed. More significantly, her red blood cells were larger, fewer in number, more fragile than normal and deformed in shape. This, she learned, was megaloblastic anemia, due to a deficiency of either folate or vitamin [B.sub.12]. If due to a lack of [B.sub.12] (which both she and her doctor suspected), it could indicate non-absorption, known as pernicious anemia. But before starting remediation, confirmation through another blood test was imperative: As her doctor warned, guessing wrong at tiffs point "could precipitate a bone marrow crisis."

Vitamin Facts

At first, Cathy was relieved to find she only had some form of anemia. Then she looked up 'pernicious': "highly injurious or destructive, tending to a Fatal issue; deadly." She promptly began research, finding that:

* Vitamin [B.sub.12] and folate work together (along with iron) to produce new red blond cells and maintain normal hemoglobin. Both also regulate normal cell division throughout the body.

* Vitamin [B.sub.12] maintains the protective myelin sheath surrounding each nerve cell and helps produce neurotransmitters (the means by which nerve cells communicate). Without [B.sub.12], nerve cells can't function normally.

* Mild "dementia" in the elderly, often viewed as inevitable, may be due to a vitamin [B.sub.12] deficiency. If so, it can be reversed.

* Excess vitamin [B.sub.12] is excreted in urine, but some--enough for 2-5 years--is also stored in the liver. However, some [B.sub.12] is needed to process folate, so a high-folate, low-[B.sub.12] diet can deplete even this reserve.

Cathy's second blood test confirmed an abysmally low [B.sub.12] level. "It was probably falling for years," said her doctor, "but was always hidden by the high folate."

Cellular Health

Further tests were needed to role out other causes of [B.sub.12] deficiency (such as undetected intestinal bleeding) and to determine if Cathy's oral absorption ability was normal, which it was. She did not have pernicious anemia, which would have necessitated massive injections of [B.sub.12] monthly for life. But she did need several months of injections as well as 100 mcg of [B.sub.12] supplements daily for sufficiently speedy recovery.

Within one year, Cathy's symptoms had completely disappeared and she felt better--both physically and mentally--than she had for years. She and Jim still eat a high-folate diet, but they have increased their [B.sub.12] intake. Both now also take daily [B.sub.12] supplements "just in case," even though Jim's [B.sub.12] tested normal. Individual metabolisms vary, but needs and absorption ability can change.

Cathy offers some prudent advice to vegans, people over 50 and anybody eating a high-folate, low-[B.sub.12] diet: "Request a blood test of your [B.sub.12] and folate levels at your next physical. Vitamin [B.sub.12] deficiency is treatable--but you can't treat what you don't know you have."

Beneficial Bs

Vitamin [B.sub.12] isn't the only important nutrient in the B vitamin family. Here's a look at a few of the other all-important Bs.

* Vitamin [B.sub.3] (niacin) aids in nerve health. It also contributes to good circulation and may help lower cholesterol. In some people, this essential nutrient can produce a harmless--though surprising--side effect. "Some people experience a kind of flush when they take niacin to help with blood flow--their flees will get very red, they may feel warm or slightly feverish; says Cynthia Frozena, a medical researcher and writer at Enzymatic Therapy. While niacin's "10-minute sunburn" certainly isn't dangerous, it can be unnerving at first.

* Vitamin [B.sub.6] (pyridoxine) can be important for pregnant women. "It was practically considered witchcraft a few years ago, but taking [B.sub.6] has been shown to help women with morning sickness and with swelling in the hands and feet," says Allan Spreen, MD, a nutrition counselor and author of Folic Acid: The Essential B Vitamin and Nutritionally Incorrect. "We've also had great results with improving carpal tunnel syndrome and other wrist and joint problems by boosting [B.sub.6]."

* Vitamin [B.sub.9] (folic acid) is also a particularly important vitamin during pregnancy. "Folio acid is a vital nutrient for fetal neurological development, so women should maintain good folic acid status long before pregnancy occurs," says Barbara Lohse Knous, professor of Human Nutrition at Kansas State University. Knous notes that the nutrient plays its role in development very early (around day 17), often before a woman is even aware that she's pregnant. Most experts recommend a folic acid supplement of 300 milligrams for any woman who is--or who might be--pregnant.

Symptoms of [B.sub.12] Deficiency

* Early warning signs: Fatigue, breathlessness, paleness, sleeping problems, headaches, forgetfulness, dizziness moodiness, irritability

* Moderate symptoms--nerve damage: Numbness or tingling of hands or feet, sore tongue, foot drop (inability to raise toe after taking step), loss of balance and coordination, profound fatigue, digestive problems, heart palpitations.

* Moderate symptoms--cognitive impairment: Memory loss, confusion, depression, disorientation, personality changes, mood swings, agitation.

* Severe symptoms: By this stage, a [B.sub.12] deficiency is unlikely to escape detection. However, if left untreated, progressive damage can lead to permanent spinal cord damage, full-blown dementia, psychosis, lymphoma (cancer of the lymph system) and death.

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