By Ken Terry

Like a lot of people in this country, Sylvia Davis, of Vista, California, practices a little morning ritual. Sometime between breakfast and her daily duties, Davis unscrews the caps on a couple of brown bottles, shakes out a few pills, and swallows each one with a sip of water. Like a lot of Americans, she has a pill habit--a habit powered not by some mute craving but by a wholesome urge for self-protection. Davis, a benefits coordinator for a public school system, takes vitamins C, E, and others, hoping to boost her immune system and shield herself from the scourges of cancer, heart disease, and more.

And who would tell her she shouldn't? These days most vitamins are enjoying the kind of good press politicians can only pray for. Recent studies have shown that antioxidants like vitamins C and E might help prevent disease by sweeping the bloodstream clear of harmful "oxygen free-radicals"--highly reactive molecules created by everything from exercise to smoking. Unimpeded, these roving oxidants damage cells' DNA, potentially leading to cancer; they may also make cholesterol more likely to clog arteries, promoting heart attacks.

Davis had read for years about these chemical demons and how higher levels of antioxidants might protect her. But until recently, like nearly everyone else, she'd always taken her vitamins pretty much on faith.

"I believe our bodies heal themselves if they have the right stuff in them," she says. "But you can't always believe the vitamin companies. They're just like all the other big companies--out for a buck. I've always thought it would be great to know how much of a vitamin you really need." So when her family doctor, Charles Moss, told her one day last year that he could help her find out, she jumped at the chance. Moss suggested a test offered by Pantox Laboratories, in San Diego. He explained that the lab would measure a whole range of vitamins, minerals, and other substances in a small sample of her blood. It would then compile a complete profile of her "antioxidant defense system." Since she had no significant health problems, Moss said, insurance probably wouldn't cover the test. That's fine, Davis replied, I want to know. I'll pay for it myself.

A few weeks later, she was back in Moss's office, flipping through a sheaf of charts. Her blood was high in vitamin E, the results showed, and low in beta-carotene. You'd be smart, the doctor told her, to cut back on your vitamin E supplements. Munching more carrots and dark green leafies wouldn't be a bad idea, either.

Is this a vision of the future? First nationwide testing for cholesterol, and now checkups for vitamins and minerals?

That day is coming soon, scientists say. A handful of labs, spurred on by the national obsession with antioxidants, have begun promoting the tests to physicians around the country. And a small number of doctors--especially those interested in alternative medicine and nutritional therapies--are starting to suggest them, not only to patients who've suffered chest pain, a heart attack, or some other illness but also to people who simply hope to hedge their bets against cancer and other long-term threats.

Surprisingly, these pioneers have gotten support from one of the nation's most eminent scientists. Biochemist Bruce Ames, director of the National Institute of Environmental Health Sciences Center at the University of California at Berkeley, calls this kind of testing the future of preventive medicine. Someday, he says, vitamins and minerals will be measured routinely, as cholesterol is today.

Ames, who serves on the scientific advisory board of Pantox Laboratories, says the main benefit of the tests would be to prod Americans to eat better. Many studies have shown lower cancer rates among people who eat lots of fruits and vegetables, rich in antioxidants.

Yet even that most credible form of health insurance may not be enough, says molecular biologist Charles Thomas, Jr., Pantox Labs' director of research, who formerly taught at Harvard Medical School. "What you eat is not really what you get," he says. "Everyone is so individual that two people eating the same diet end up with different levels of these things in their blood."

That's certainly true of the B vitamins. As people age, their ability to absorb B vitamins, including folic acid, can become impaired. If both a youngster and an older person eat a spinach salad, the youngster's likely to end up with more folic acid in his bloodstream. What's more, some people are born with a gene that raises their demand for folic acid. With too little of it, they run an added danger of heart attack and stroke--and are at higher risk of having babies with certain types of birth defects.

Ames says studies also show that a shortage of folic acid leads to chromosome damage--and possibly cancerous cell growth--and that running low on vitamin C can likewise make the body more vulnerable to cancer. Given cancer's toll in suffering and expense, he says, we should start testing for those vitamins now.

But before you rush off to have your own levels tested, there are some things you should know. Not every nutrition expert thinks these tests are such a great idea. Getting the test could well leave you poorer--and no wiser. Here are the answers to several crucial questions:

Where would I go to get tested?

You'd have to see a medical professional--perhaps one with a more experimental bent than your regular family physician--to get a blood sample taken and shipped in dry ice to a lab. Pantox is one of several small labs that specialize in this kind of testing. Among the others are SpectraCell, in Houston; Liberty Testing Laboratory, in Brooklyn, New York; and MetaMetrix, in Atlanta.

Some of the large clinical laboratories to which doctors have always sent blood samples also run tests for vitamins. But they don't advertise this service; most physicians order them only if a patient shows symptoms of a nutrient deficiency or overload.

What do the labs test for?

Pantox measures the levels of more than 20 substances in a blood sample, including the fat-soluble vitamins E, A, and beta-carotene; water-soluble vitamin C; HDL and LDL cholesterol; various forms of iron; and several other health indicators such as glucose and homocysteine, an amino acid linked to an increased risk of heart disease and stroke.

Because it specializes in antioxidants, Pantox hasn't concerned itself with vitamin D or the B vitamins. In the near future, though, the company plans to expand its test to include folic acid.

Are the tests expensive?

Pantox charges $275 to test for more than 20 antioxidants. SpectraCell gets $425 for 19 nutrients such as glucose and calcium; if you also want an antioxidant profile, the cost is an additional $500.

That's fairly steep, but consider that the Laboratory Corporation of America, a large clinical lab, charges as much as $200 to test just one nutrient. A battery of tests similar to what Pantox or SpectraCell offers could cost well over $1,000.

Bruce Ames thinks all these prices are too high. If the tests were automated and done in bulk, he says, a full series should cost only $100. In the meantime, health insurers will sometimes foot the bill. Doctors prescribing nutrient tests report that traditional, fee-for-service insurance companies are more likely to pay for them than are HMOs. In either case, coverage is most likely with a diagnosis of high cholesterol, diabetes, arthritis, or some other serious condition.

How reliable are the results?

The pantox-style labs are very good at pinpointing the vitamin and mineral levels in a sample of blood. The problem, surprisingly, is that no one really knows what the ideal levels ought to be. True, nutritionists do know what our bodies need to avoid deficiency illnesses like scurvy and rickets. The doses are spelled out in those side-of-the-cereal-box values called recommended daily allowances, or RDAs. But when it comes to defense against cancer and heart disease, researchers are still mostly guessing.
When Pantox profiles a patient, the lab compares the data with figures from the 4,000 other blood samples it's analyzed to date. A person's levels are considered good if they're in the upper half--but not right at the top end--of those 4,000 test results. (People at the very top may have too much of a particular nutrient.)

But it's unclear how representative that fairly small group is. Many of the people who've contributed samples to date have serious illnesses such as diabetes, cancer, or arthritis--any of which might skew the readings, though no one really knows which way or by how much. There's no large database of typical levels among healthy Americans.

That's no reason to shun the test, says Charles Thomas, Pantox's research director. He says any illness-linked variations "wash out" among the thousands of samples. And even if they did skew the data, he adds, you'd still be better off among the people with above-average levels.

Many nutrition scientists aren't convinced. They point out that vitamins and minerals in the bloodstream don't necessarily reflect levels in the body's other tissues. "Some parts of the body may be getting less than others," says Peter Greenwald, director of cancer prevention and control for the National Cancer Institute, "especially in people who have risk factors such as smoking."

There's another problem, adds Walter Willett, professor of epidemiology and nutrition at the Harvard School of Public Health. The tests may measure what's there at the moment your blood is drawn, he says, but nutrient levels can vary from day to day and from month to month.

"I wouldn't place too much faith in blood tests as a predictor of health," Greenwald says. "I don't think we're sure how to interpret them."

This is why SpectraCell claims its test is superior. Instead of measuring simple vitamin levels, this lab checks the speed at which white blood cells divide when a vitamin is added. "If the rate increases, that tells you the cell was deficient in that nutrient," says SpectraCell's president, William Stanberry. The vigor of these cells, he asserts, reflects the strength of a person's immune system as well as how much the body is being "stressed" by oxidants such as cigarette smoke.

But this notion rests on shaky assumptions, says Ishwarlal Jialal, associate professor of internal medicine and pathology at the University of Texas Southwestern Medical Center, in Dallas. Even if white blood cells in a sample respond to vitamins, he says, it's naive to suggest that a few cells dosed outside the body can reveal anything meaningful about the overall vigor of the body's complex immune system.

Jialal doesn't place much faith in the Pantox-style tests, either. They may be accurate, he says, but they're meaningless without more reliable information on what good those many compounds are doing inside the body. "We don't have a test that can tell, among five people, that one clearly has more oxidative stress and should take supplements," he says.

Once I get tested, then what?

If what you get is a Pantox-style blood test, your physician will show you the lab's written interpretation and some bar graphs comparing your levels to the larger group's. Considering your overall health, he'll tell which vitamins or minerals you might need to boost or cut back on, and by how much. He might also encourage you to eat more of particular foods, especially certain vitamin-rich fruits or vegetables, then come back for a follow-up test (and another $275 fee).

"It isn't easy for any of us to change what we eat," says Bruce Ames of UC Berkeley. "But if a doctor warns you and points out how your nutrient levels compare, it might have an effect."

That's fine, so long as people don't take the readings too literally, says Dean Ornish, director of the Preventive Medicine Research Institute, in Sausalito, California. Even if the tests prove reliable, he says, they won't help if people who learn they're running low simply gulp vitamin pills and then go on eating junk food, living high-stress lives, and never exercising.

Why not just skip the test and take supplements?

Many people do just that and live happily ever after. But promoters of the new tests say that without the inside view people may buy supplements needlessly or, on the other hand, believe they've upped their vitamin levels when they really haven't. Charles Thomas remembers a man who was eating lots of vegetables, as well as taking supplements--but he smoked. The test showed no beta-carotene in his system and little vitamin C. In contrast, he cites a woman who had plenty of all the key antioxidants in her blood. "I figured she was supplementing everything," he says. "But I found out that she avoided nutritional supplements of any type. She simply ate a diet that was rich in fruits and vegetables, with some meat."

What's more, advocates say, getting tested could keep some people who are now using vitamin supplements from taking overdoses. While megadoses of vitamin E--up to 1,000 IUs a day--are generally considered safe, one study found that high doses seemed to slightly raise the risk of hemorrhagic stroke (the type caused by bleeding in the brain). Similarly, doses of vitamin C are considered safe up to 1,000 mg a day, but an overload in genetically susceptible people can trigger a release of stored iron, which damages the heart and other organs. And getting too much vitamin A early in pregnancy can cause birth defects. So test results could pull some overeager pill-poppers back from the edge.

People with minor health complaints may also benefit from getting tested. Karen Diedrich, a patient of physician Frank Varese, in Laguna Hills, California, was feeling tired all the time and kept coming down with colds. "I had an arsenal of pills, and I wasn't sure how much I was supposed to take," says the 33-year-old secretary. The Pantox test revealed that she was running low on iron. She adjusted her supplement mix and began eating more iron-rich foods--red meat, tofu, and spinach. Her health improved, she says.

Yet beyond personal stories like Karen Diedrich's, and the many promising studies, there's still no guarantee that fine-tuning your nutrients will prevent serious illness. Current nutrition research is filled with gaps and contradictions--such as the 1994 finding in Finland that smokers taking beta-carotene were more likely to develop cancer. Sylvia Davis's physician, Charles Moss, acknowledges that more research is needed. In the meantime, however, he points to strong existing evidence, like that linking vitamin E with a lower danger of heart disease.

"I'm willing to let my patients take the tiny risks of nutrient therapy," Moss says, "rather than wait the ten or 20 years it'll take to figure all this out."

(c) 1996 HEALTH magazine