A user’s guide to vitamins and minerals, from calcium to omega-3s.
Carmel Wroth | Sept/Oct 2009 issue
Natto, a brown, gluey mass of fermented soybeans that emits an ammoniac stench, is served oozing over a bed of rice. In some regions of Japan, natto is a breakfast staple. To most non-Japanese, however, it’s an acquired taste at best. Yet the dish is more than a culinary curiosity. It may be a key to understanding the importance of vitamins and minerals to health.
Natto is rich in micronutrients, especially vitamin K, which means regular natto eaters take in more vitamin K than most other people. The fact that natto isn’t, shall we say, universally savored has allowed nutrition researchers to conduct population studies in Japan showing that natto aficionados have lower incidences of heart disease and bone fractures. Bruce Ames and Joyce McCann, nutrition researchers at the Children’s Hospital Oakland Research Institute in California, have reviewed research into natto, along with a body of other evidence. They conclude that vitamin K, which has so far only been known to support blood coagulation, could be important for heart health and bones as well.
This vitamin K analysis supports Ames’ overall theory that shortfalls of essential micronutrients—minerals, vitamins, fatty acids and other biochemicals—may lead to many of the chronic diseases that afflict us as we age. While emphasizing that healthy eating is key, Ames, along with many other experts in mainstream as well as alternative medicine, argues that nutritional supplements can play a valuable role in health as well.
The modern diet is “energy rich and nutrient poor,” Ames says. On average we eat too much processed flour and sugar, poor-quality fats and meats and not enough fruit, vegetables, nuts, beans and whole grains, which have more nutrients per calorie. “If people fill themselves with sugary soft drinks they’re going to be full, yet they’re starving for micronutrients,” says Ames.
Ames and McCann aren’t alone in finding a link between chronic disease and lack of micronutrients. It’s well established that poor dietary patterns increase the risk of many illnesses. A lot of people turn to supplements in the belief that it will lessen the risk. This has contributed to a dramatic expansion in the supplement industry over the past several decades. At least 50 percent of Americans take a supplement, and 35 percent take a multivitamin. Some $4.2 billion was spent on multivitamins alone in 2005, according to the Council for Responsible Nutrition, a trade organization representing the industry.
Ames says nutrient shortfalls in modern diets are now so widespread, and the increased risk of major chronic disease so likely, that we can’t afford to wait for definitive scientific proof of the role of supplements or for our habits at the table to improve. If you aren’t sure you’re eating a perfect diet (and who among us is certain we eat five to nine servings of fresh produce each day?), supplements can even the score. “My feeling is you try to eat a good balanced diet, cut out sugary soft drinks and empty calories, but take a multivitamin as insurance,” says Ames.
Most of us already know we need to eat well to stay healthy. Still, when it comes to diet, a lot of us just aren’t able to put our knowledge where our mouths are. “We are inundated with appealing advertisements for fast foods, highly sweetened beverages that provide empty calories, and fad diets,” physician and alternative medicine expert Andrew Weil wrote in an e-mail interview. “Compounding the media message to ‘eat more of everything’ is the plethora of highly processed and refined foods on the market, easy access to rapidly digestible carbohydrates, busy schedules that preclude cooking at home, and frequent travel.”
Studies have repeatedly shown that the typical Western diet corresponds to higher risks of heart disease, cancer and other chronic conditions, such as diabetes. Ames has a theory about how the diet-disease connection may work. “There are about 40 micronutrients you need to run your metabolism,” says Ames. “If you don’t get any one of them, you die. What we’re learning is the consequence of not getting enough is that your body cuts back on certain functions that affect long-term health. … When you’re short of micronutrients, there’s a lot of hidden damage going on.”
The World Health Organization has stated that diet is second only to smoking as a preventable cause of cancer. Indeed, the United States Department of Agriculture (USDA), American Heart Association and American Cancer Society have made dietary recommendations a central part of their disease-prevention messages, suggesting we eat more fruit and vegetables, replace refined carbs with whole grains and cut down on junk food. Yet according to Centers for Disease Control and Prevention (CDC) surveys, only 11 percent of Americans meet the USDA’s guidelines for eating five to nine servings of fresh fruit and vegetables daily. The nutrient shortfalls are dramatic. According to data gathered from 1999 to 2002 and compiled by the CDC, 93 percent of Americans don’t get enough vitamin E, 56 percent don’t get enough magnesium, 31 percent don’t get enough vitamin C and 12 percent don’t get enough zinc. Another CDC survey indicated many people are low on vitamin K, calcium and potassium, and many seniors lack B vitamins.
The first step to fixing nutrient shortfalls is to improve diet, says Yale University nutrition researcher David Katz. The 40 or so isolated micronutrients that scientists study—and supplement companies pack into capsules—are only a fraction of the array of organic compounds found in food. Indeed, many vitamins are not a single “vitamin” but a family of compounds. And our bodies need these complementary nutrients to make use of these vitamins. When you get your vitamin C in a piece of fruit, for example, it comes with a lot of other ingredients—fiber, antioxidants and trace minerals—that might help you more consumed together than if you down vitamin C alone in a supplement. “It may be that the active ingredient in broccoli is broccoli,” says Katz. “People who don’t want to eat broccoli and take a vitamin instead will probably be disappointed. If you want the benefits of nutrients in foods, you need to eat foods rich in nutrients.”
The trouble, argues Lynne McTaggart, editor of the monthly U.K. health journal What Doctors Don’t Tell You, is that even if you do eat your broccoli, you may not be getting what you need. “Food isn’t as nutritious as it once was,” she says, pointing to research that shows a decrease in nutrient levels in produce compared with what was harvested a few decades ago. In 2007, Brian Halweil, a researcher at the Worldwatch Institute, reviewed several projects that examined nutrient levels in produce. In a report published by the Organic Center of Boulder, Colorado, he concluded that breeding for high yields has diluted the nutritional quality of the plants we eat. According to data collected by government agencies in the U.S. and U.K., modern harvests are lower in many nutrients than those in the 1940s and 1950s, including magnesium, iron, potassium, calcium, riboflavin and vitamin C.
Halweil also highlighted research suggesting that conventional produce grown in poor soils and bathed in synthetic fertilizers may have lower levels of nutrients than that grown with organic techniques. But even organic food has come in for criticism; a report commissioned by the U.K. Food Standards Agency (FSA) found no substantial difference in nutritional content between organic and conventional food, a finding strongly contested by the Organic Center, the U.K. Soil Association and others.
Still, to many nutrition experts, supplements make a lot of sense. “Even people who consistently eat well can benefit from supplementation,” says Weil. “Optimal intakes of key nutrients, in amounts sufficient to enhance health beyond the prevention of deficiency states, can be difficult to obtain through diet alone.”
Vitamins were first discovered in the early 20th century when researchers observed that certain diseases correlate to dietary patterns. After the widespread adoption of milled rice throughout Asia, for example, there was a sharp increase in beriberi, a debilitating disease of the nervous system. Researchers eventually determined that this was caused by a deficiency of an organic compound, thiamin (vitamin B1), which disappeared from Asian diets along with the rice husks. Thiamin is now used to prevent the disease.
In the 1920s and 1930s, scientists discovered links between scurvy and vitamin C, blindness and vitamin A, and rickets and vitamin D. Though these deficiency diseases have been virtually eliminated in the West, through fortification and greater access to a wide variety of nourishing foods, many people in the developing world still suffer from them.
While most Americans don’t suffer from overt deficiencies, Ames argues many of us may be suffering from less obvious shortfalls that contribute to disease. Nevertheless, research into vitamins and other micronutrients produces conflicting results. In 2002, the Journal of the American Medical Association published a paper recommending that everyone take multivitamins. But earlier this year, a study of 162,000 post-menopausal women at the Fred Hutchinson Cancer Research Center in Seattle, Washington, found no reduction of mortality from cancer or other causes among women who’d taken combined multivitamin and mineral supplements for eight years. “One study will show benefit and then another will come out and show no benefit,” says nutritionist and author of What to Eat
Marion Nestle. “What that shows me is that whatever is going on is so trivial that you can’t design a study big enough to show effect.”
Children’s Hospital of Oakland Research Institute scientist McCann argues that the real problem with long-term studies like this is that they’re inherently flawed. Since long-term health is what’s at stake, a good study would need to track people for many years and have some way of controlling exactly what they ate, whether they consistently took the pills (or as controls, didn’t take them) and all the other lifestyle factors that could color the results. “To directly demonstrate that experimentally is almost impossible,” McCann says.
McTaggart argues that many of the studies demonstrating the effectiveness of supplements don’t get the attention they deserve because the medical community has a bias against nutritional healing. The assumption among medical scientists, McTaggart says, is that “the body is a machine that gets broken and there’s only one way to fix it—with chemicals or surgery.” In contrast, nutritional healing treats the body as a dynamic organism that can be affected by its environment in subtle ways, including through deficiencies in diet. “There are many diseases that could be a long-term consequence of being deficient in one or more nutrients,” argues McTaggart. “There’s a lot of evidence that vitamins and minerals protect against illness.”
Jeffrey Blumberg, a nutrition scientist at the Tufts University Friedman School of Nutrition Science and Policy in Boston, Massachusetts, points out that certain benefits of supplements have been verified. Vitamins A, C and E can help protect against age-related macular degeneration, an eye condition that can lead to blindness, and vitamin E boosts immune response. A combination of vitamin E and selenium looks promising for fending off cancer, he says, and several studies support a potential cancer prevention benefit from vitamin D and calcium. There’s also good research linking omega-3 supplements to reduced risk of heart attack. “About 60 years ago, we started fortifying some staples like milk because it was clear that people were not meeting the requirements,” says Blumberg. “We put iodine in salt and now we’re putting folic acid in refined flour. If we fortify the diet, taking supplements is not any different.”
But which supplements should we choose? How many should we take? And in what form should we take them? It’s easy to be confused by the choices in the supermarket and the claims on the labels. But leading scientists in the field of nutrition and supplements agree on a few basics, outlined below, that are generally helpful for healthy adults. If you’re not sure what’s good for you, or if you seek nutritional support for a specific condition, see a qualified nutritionist or naturopathic doctor. The key to choosing supplements is to analyze your own dietary patterns, says Yale’s David Katz. “Look at your diet and figure out what nutrient you might be deficient in. Make the supplements match the likely pattern of gaps in your diet.”
Since it’s hard to determine which nutrients you might be missing, taking a multivitamin supplement is a good choice for many, says Blumberg. “Only about 3 percent of Americans follow the dietary guidelines. I think it’s a prudent thing for everyone to take a multivitamin-mineral supplement.”
Blumberg, like many others, recommends choosing a multivitamin containing moderate dosages of nutrients, between 100 and 200 percent of the U.S. National Academy of Sciences’ Dietary Reference Intake levels. Avoid pills that have high amounts of single nutrients. Irwin Rosenberg, a Tufts University scientist who helped set these levels, cautions against taking too much of vitamins A and D, which can accumulate in the body and become toxic, leading to liver damage. He also says to watch out for excessive minerals, many of which can be harmful in high doses.
In addition, says Victoria Maizes, director of the Arizona Center for Integrative Medicine, avoid any supplement that contains pre-formed vitamin A, which appears only in food from animal sources and can be harmful in high doses. Read labels carefully, she says, and choose a pill that contains mixed carotenoids, compounds found in colorful fruits and vegetables that are formed into vitamin A in the body. Carotenoids have additional antioxidant effects and no risk of toxicity. Also, check what type of vitamin E is in the pill; the best is natural mixed tocopherols, which are absorbed more efficiently. Finally, it’s a good idea to choose a pill designed for your gender and age, as nutrient needs vary. Women of childbearing age, for example, need to make sure they’re getting enough iron, so multivitamins for women typically have more iron. Older people have different requirements as well, and in general need more vitamin D and vitamin B12.
Calcium, vitamin D and magnesium
Since calcium, which helps protect bones, is a bulky molecule, most multivitamins don’t have more than about 10 percent of the daily requirement, says Blumberg, so an additional pill is a good idea. Your body can’t fully assimilate calcium without vitamin D and magnesium, so if you decide to take a supplement, choose one that includes all three.
Bone health is affected by protein-rich foods and excessive sweets, which disrupt the acid/alkaline balance in our bodies. “The body doesn’t want blood to be acidic,” says Amy Lanou, a nutrition scientist at the University of North Carolina at Asheville and author of Building Bone Vitality, “so it pulls calcium compounds from bones to neutralize acidity.” This contributes to the high rate of bone fractures and osteoporosis among the elderly. To protect your bones, Lanou recommends eating more alkalinizing foods—beans, whole grains and vegetables.
Taking vitamin D alone, or with calcium, may decrease the risk of some cancers, yet many of us don’t get enough vitamin D. The vitamin doesn’t appear in most foods; the primary way we get it is through our skin when it’s exposed to sunlight. The trouble is, many of us don’t go out in the sun enough. Yale nutrition researcher Katz says most people with darker skin living in northern hemispheres are deficient. To ensure enough vitamin D, many experts now recommend about 20 minutes a day of sun, without sunblock, or a supplement.
Omega-3 fatty acids
Essential fatty acids found in vegetable and animal fats are important building blocks for cells and regulate many of the body’s functions. Evidence is mounting that the typical modern diet, which is high in animal fats and vegetable oils, overemphasizes omega-6 fatty acids, which can cause inflammation. They also deliver too few of the anti-inflammatory omega-3 fatty acids found in green plants, certain nuts and seeds, fatty fish and fats from animals that graze on grass.
To combat this problem, experts recommend increasing omega-3 intake with a fish oil supplement. David Servan-Schreiber, a physician and professor of psychiatry at the University of Pittsburgh School of Medicine as well as author of Anticancer: A New Way of Life, says having the right balance of essential fatty acids can reduce the body’s inflammatory response and protect against illness. “All the chronic degenerative diseases stem from a high level of inflammation in the body,” he says.
The U.S. National Institutes of Health (NIH) reports that most Americans get about 10 times more omega-6 fatty acids than omega-3s; other estimates suggest that number may be as high as 25 times more. The NIH has determined that adequate consumption of omega-3s can protect against heart disease, and the American Heart Association recommends the supplement for heart disease patients. Other research suggests omega-3s may also protect against cancer, bone disease and mood disorders, including depression, and support brain health as we age. Research by Oxford University physiologist Bernard Gesch even points to a decrease in the incidence of violence and aggression among prisoners who took a daily supplement of vitamins, minerals and omega-3s, compared with a control group that only received placebos.
One reason many of us may have an omega imbalance is that the meat, dairy and eggs we typically consume are from animals raised on corn and soy. Corn and soy are high in omega-6 fatty acids, while grass is rich in omega-3s. Most packaged sweets and snacks contain soy oil high in omega-6s. To get a better omega balance, choose grass-fed sources for animal products and eat fewer packaged snacks, fried foods and cheap vegetable oils, such as salad dressings made with corn or soy oil. And eat more fish, beans, tofu, flax seeds and walnuts.
Yale nutrition researcher Katz recommends taking supplements made from dehydrated whole fruits and vegetables. Whole foods supplements contain more of what you’d find in the plant, so they’re more likely to deliver the best antioxidant benefit, since isolated compounds tend to have fewer antioxidants than whole foods. Experts suggest avoiding ingredients such as dyes, synthetic sweeteners, flavorings and preservatives.
Another point to consider, particularly regarding multivitamins, is whether you have the discipline to take more than one pill a day. One-a-day pills usually contain isolated nutrients. Some supplements are formulated with extra food-based ingredients and these need to be taken several times a day to get the suggested amount of nutrients. But they may also have added benefits. “The food-grown stuff is closer to food and lower in potency and is very well absorbed,” says Don Summerfield, co-founder of Pharmaca Integrative Pharmacies, a chain of natural medicine stores based in Boulder, Colorado.
Supplements can come in either tablet or capsule form or as a liquid. There’s no real difference, according to Katz, unless the tablet is poorly formulated and doesn’t break down well in the digestive tract. To avoid that, choose a high-quality supplement from a company that follows federal Current Good Manufacturing Practices or has a seal from United States Pharmacopeia, NSF International or ConsumerLab. If you’re not sure about quality, ConsumerLab independently tests supplements to verify that they contain the alleged ingredients and are free of toxins.
But all experts agree good health isn’t simply a matter of popping pills. “The basic principle is that supplements are not substitutes,” says Tuft University’s Blumberg. “You can’t eat a terrible diet and take supplements and think you are okay.”
“While it is possible to obtain sufficient amounts of important nutrients through a healthy diet, it is nonetheless difficult,” concludes Weil. “This is especially true for micronutrients, including vitamins, minerals, fiber and the range of unique phytochemicals. Improving your diet will certainly contribute to your health, but getting a consistent level of nutrient intake through diet alone is a challenge, one best met through appropriate supplementation.” So, if natto is just not your thing, you can always try a supplement.
Carmel Wroth has sworn to give up junk food, but can still sometimes be found nervously clutching a soft drink.