Vitamin [B.sub.12] and the vegetarian diet: are you getting enough?

Vegetarian diets--whether lacto, ovo-lacto, or vegan--can each easily supply all the nutrients needed for vigorous good health--with the possibility of one exception vitamin [B.sub.12]. Actually, lacto- and ovo-lactovegetarian diets usually include an adequate amount of vitamin [B.sub.12] because they contain dairy products, and these products do generally supply enough vitamin [B.sub.12]. As long as you're able to absorb this nutrient, you should be just fine. A vegan diet, however, because it contains no animal products, is different. If vitamin [B.sub.12] isn't coming from food, it needs to come from somewhere else.

The amount of [B.sub.12] needed is small--estimates range from 1 microgram to 6 micrograms per day. And even in larger amounts, it's been found to be harmless.

"Despite the need for such a miniscule amount of the vitamin," says Suzanne Havala Hobbs, Dr. Ph., M.S., R.D., and adjunct assistant professor and director of Carolina Health Summit, at the University of North Carolina at Chapel Hill, "the stakes are high if you don't get what you need."

But simply taking in an adequate amount of [B.sub.12] is not enough. Your body must absorb it too--and not everyone's does, whether they are vegetarian or not. The consequences of getting too little--or absorbing too little--vitamin [B.sub.12] are serious. They are also easily avoided.

To see why this nutrient is important, let's look at what it does. [B.sub.12] stimulates the body's use of proteins, fats, and carbohydrates, and it boosts energy. It's necessary for cell division, helps maintain healthy blood, contributes to the well-being of the entire nervous system, and protects against heart disease. It also guards against memory loss and mental deterioration that can resemble Alzheimer's disease.

One of the most serious consequences of too little vitamin [B.sub.12] is pernicious anemia and its accompanying neurological problems. The symptoms may be subtle at first, but the consequences are not.

So What Exactly Is Pernicious Anemia?

"It's a widespread disease," says John W. Tracy, M.D., a family practitioner at Randolph Family Practice in Charlotte, North Carolina, "widespread in the sense that it affects a number of organ systems in the body. It's not only anemia, but you lose the hemoglobin, you lose the white cells, you lose platelet function. It's a neurologic disease. People will get what's called ataxia, meaning they stumble around and can't walk straight. They get numbness of their hands and feet."

Other symptoms include moodiness and depression, memory loss, difficulty sleeping, and dizziness. There may also be apathy, light-headedness, and shortness of breath. And, because your body is making fewer infection-fighting white blood cells, you may be getting sick more often. Further, because your body may not be replacing quickly enough the cells that line your intestine, you may suffer from appetite loss, vomiting, and diarrhea.

"It's a debilitating disease," he continues, "and it's also, to some extent, irreversible. Once you get the full neurologic manifestations of [B.sub.12] deficiency in pernicious anemia, you're probably not going to recover. Oh, you're going to recover some, but not completely."

Besides strict vegetarians (vegans), there are certain groups of people who are more likely than others to suffer from a vitamin [B.sub.12] deficiency, including pregnant and nursing women, smokers, those taking prescription potassium supplements long-term, and those who are taking the prescription drug omeprazole (Prilosec) for severe heartburn or ulcers.

Additionally, those who have had part of the stomach surgically removed may no longer have enough intrinsic factor (made in the stomach) necessary for utilizing [B.sub.12]. Also, anyone who has had his or her ileum removed (because of Crohn's disease, for example) needs to pay special attention to vitamin [B.sub.12], because the ileum is the portion of the intestine where this vitamin is absorbed.

The largest group who may be at risk of [B.sub.12] deficiency, however, may be people over age 50. It's estimated that up to 30 percent of older people (whether they are vegetarian or not) may be unable to adequately absorb [B.sub.12] because of a decrease in stomach acid.

If you fit into any of these categories, you may want to discuss with your doctor whether you should take a vitamin [B.sub.12] supplement or, in some cases, [B.sub.12] shots. And if you are one of those people who cannot abide shots, you are still not out of options--[B.sub.12] is also available in a nasal spray, a nasal gel, and in lozenges to put under your tongue.

Fortunately, and probably because vitamin [B.sub.12] is an essential part of so many of the body's functions, says Dr. Havala Hobbs, "the body hoards it and recycles it and is very effective at hanging onto what it already has."

"It tends to be a cofactor in biochemical reactions in the body," says Dr. Tracy, "which means it's not destroyed so much. It's going to be reused. But you will ultimately run out of it."

There is one "source" of vitamin [B.sub.12] that needs to be mentioned here, and that's dirt--yes, dirt. It used to be thought by some that a reliable way to get vitamin [B.sub.12] in the diet (especially for vegans) was to refrain from thoroughly scrubbing fresh fruits and vegetables--in other words, leaving some of the dirt on. However, besides the fact that this is entirely unappetizing (Who wants to eat dirt?), it's also a health hazard. While it may be possible to some extent to get some vitamin [B.sub.12] from the soil in this way, says Dr. Tracy, we can get other things as well--E. coli and tetanus, for example, "and who knows what else." Inadequately washed produce is not recommended.

So what is the best way to get [B.sub.12]? Actually, there are many good ways, and you can choose the way (or ways) that work best. Eggs and dairy products can supply it. But what if you don't want to eat these or for some reason cannot tolerate them?

It used to be thought that foods such as tempeh, miso, tamari, bean sprouts, and sea vegetables such as kelp and spirulina were good sources. But these foods are now believed not to contain the form of vitamin [B.sub.12] that the body can use.

There are alternatives we can count on, though, ones that are easily available and that can fit right into our daily lives quite readily.

One such source is foods fortified with vitamin [B.sub.12]. Breakfast cereals are a good example. Soy milk is another. Tofu and some meat substitutes may be fortified as well. Get into the habit of checking nutritional labels to see which products contain vitamin [B.sub.12] and those that do not.

By far, though, the easiest way to make sure you get the necessary vitamin [B.sub.12] is simply to take a supplement. This can be a multivitamin or a multivitamin and mineral supplement, or simply a [B.sub.12] supplement.

And if you want to really be sure you get enough [B.sub.12], it's fine to take a supplement and eat fortified foods. Your body will adapt its level of absorption according to how much it needs.

If you've been following a vegan or near-vegan diet for three years or more or if, for any of the other reasons we've mentioned here, you're concerned about whether you are adequately absorbing vitamin [B.sub.12], by all means get a blood test to measure your body's levels. Besides being fast and simple, the test will give you peace of mind--or point out a problem, if there is one, so you can work to correct it.

Getting too little vitamin [B.sub.12] can be tragic. Getting enough is easy. If you're in any doubt at all about which you are doing, see your doctor.

Peggy Rynk writes on health issues from Charlotte, North Carolina.