September 23, 2011, Vancouver Sun, Sara Schmidt

Coca-Cola Ltd. has reduced drastically the amount of Vitamin A in one of its fruit drinks after nutrition experts complained the elevated level could pose a health risk.

The cola giant confirmed Thursday that its Orange Mango FUZE Vitalize drink is now boosted with about onethird of the amount of vitamin A it contained just a few months ago. The company began producing the reformulated beverage in June. The product no longer contains what the government calls the “tolerable upper intake level” for adults, and instead contains the recommended daily dose of the vitamin for men.

The maximum daily level, set at 3,000 mcg (retinol activity equivalents), was established after evidence showed that consuming more vitamin A in the retinol form – the type contained in this drink – may cause liver abnormalities and, if consumed by pregnant women, birth defects. The change now sets the level at 907 mcg.

“We are continually monitoring consumer needs and feedback with regards to our products for opportunities to improve our portfolio to ensure we are providing the best product possible,” Coca-Cola Refreshments Canada said in a statement.

Nutrition experts are welcoming the news, but say the voluntary change to reduce the vitamin A in each 547-ml bottle shows why Health Canada needs to overhaul the way it regulates fortified food and drink products.

“I’m happy they did this. The good news or positive spin is they made a change in response to this concern, even if it took a while,” said Susan Whiting, a professor of nutrition of University of Saskatchewan.

Whiting and Ottawa-based nutrition specialist Yoni Freedhoff complained separately to the company last year.

“I’m still wondering, ‘where’s Health Canada on this?’” added Whiting. “They never should have had it at that level to begin with. It should never have been permitted and it’s just an example where these vitamin waters are deemed to be unregulated.”

The FUZE drink is one of hundreds of “food-like” products on store shelves in Canada sold as natural health products (NHP). Other “food-like” NHPs include cereal bars, puddings and candies.

Under the food regulations, Health Canada limits the ability of companies to fortify products with nutrients at their discretion to ensure the integrity of the food supply and make sure people don’t overconsume certain nutrients.

In the absence of a permissive discretionary food fortification policy, the industry has called the use of the natural health product designation as a “workaround” to these rules. The chief of Health Canada’s nutrition evaluation division has characterized the situation as a “legal loophole” in internal correspondence obtained under access to information legislation.

Whiting said the effect of regulating products like FUZE Vitalize as NHPs rather than foods is that products are evaluated on an individual basis rather than a wider perspective of nutrient intake in the food supply.

Internal Health Canada records, dated April 2009, indicate that departmental experts flagged this potential problem with evaluating “oneoff requests” for NHP licences because they fail to consider the “impact on the whole food supply, recognizing that many of these products are going to be used as part of their food intake by many consumers.”

The department has been working on a plan for the last few years to transition “foodlike” products sold as natural health products into the food regulatory framework.

Vitamin A, found in retinol form in animal and dairy products or carotene form in fruits and vegetables, helps maintain immune function, eyesight and skin membranes.

But if a pregnant woman over-consumes retinol during her pregnancy, there’s a risk of birth defects. And in older adults, there is a risk of liver damage.

Health Canada’s recommended daily dietary intake for men is 900 mcg of vitamin A and 700 mcg for women.

Read more: http://www.vancouversun.com/health/Coca+Cola+cuts+vitamin+content+fruit+beverage/5446524/story.html#ixzz1Z8qq2d8A

via Coca-Cola cuts vitamin A content in fruit beverage.

August 23, 2011, Washington Post, Jennifer LaRue Huget

In an ideal world, no one would need dietary supplements. Our balanced diets would provide all the vitamins, minerals and other nutrients our bodies need.

Alas, the world of American eating is far from ideal. And that, some nutrition experts and supplement advocates argue, is why we need dietary supplements.

The latest federal data show that more than half of U.S. adults use dietary supplements, mostly multivitamins. But do we really need all those pills?

Depends on whom you ask. The latest version of the federal Dietary Guidelines for Americans urges us to get our nutrients primarily from food:

“A fundamental premise of the Dietary Guidelines is that nutrients should come primarily from foods. Foods in nutrient-dense, mostly intact forms contain not only the essential vitamins and minerals that are often contained in nutrient supplements, but also dietary fiber and other naturally occurring substances that may have positive health effects.”

This “food first” approach is based on the emerging understanding that our bodies may process nutrients in food differently from those supplied by supplements and that foods contain scores of compounds whose synergy may be what makes them good for us.

The document also points out that “sufficient evidence is not available to support a recommendation for or against the use of multivitamin/mineral supplements in the primary prevention of chronic disease for the healthy American population.”

But, as I wrote in 2009, meeting your daily dietary needs without using supplements is a challenge, even when you’re choosing ultra-healthful foods under a professional dietitian’s guidance.

It’s a widespread challenge. Society has “invested a lot in the science behind the Dietary Guidelines for Americans,” says Duffy MacKay, vice president for scientific and regulatory affairs for the Council for Responsible Nutrition, a dietary supplement trade group. “When you think about people and what they’re eating, a significant number are not meeting those benchmarks.”

Robert Post, deputy director of the U.S. Department of Agriculture’s Center for Nutrition Policy and Promotion, says too few Americans are meeting all their nutritional requirements and that dietary supplements, used sensibly, can help fill gaps in our diets. In particular, he notes, the guidelines single out four “nutrients of concern” that most of us need more of to maintain good health: potassium, Vitamin D, calcium and fiber (see chart).

But Post, like the guidelines, calls for people to get their fill of those four nutrients from food and to consider supplements only for a handful of dietary deficiencies related to our stage of life and dietary preferences. Those include:

Iron: Women who are able to become pregnant need more iron, especially heme iron, which the body absorbs more readily than non-heme iron. Heme iron is found in lean meat and poultry; non-heme iron is in white beans, lentils, spinach, enriched breads and cereals. Foods rich in Vitamin C can aid iron absorption. Adult males need just 8 mg of iron per day; women need 18 mg, and pregnant women need 27 mg.

Read more at Dietary supplements: Do we need them, or can we get all our nutrients from food? – The Washington Post.

Older women who are overweight or obese and lose more than 15 percent of their body weight could significantly boost their levels of vitamin D.

Since vitamin D is generally lower in persons with obesity, it is possible that low vitamin D could account, in part, for the link between obesity and diseases such as cancer, heart disease and diabetes. The study, conducted in Seattle, America indicates that the surge in vitamin D could help scientists explore new avenues for the prevention of these chronic diseases.

Vitamin D is fat-soluble nutrient that plays many important roles in the body, including promoting calcium absorption and is needed for bone growth and bone healing. Along with calcium, vitamin D helps protect older adults from osteoporosis. The nutrient also influences cell growth, neuromuscular and immune function, and reduces inflammation. Many gene-encoding proteins that regulate cell proliferation, differentiation, and apoptosis (programmed cell death) are modulated in part by the vitamin.

It’s found in certain foods, such as fatty fish, and produced naturally in the body through exposure of skin to sunlight. Just 10 minutes of sun a day is enough to trigger adequate vitamin D production. The estimated average requirement via diet or supplementation is 400 international units per day for most adults. The optimal blood level of vitamin D is thought to be between 20 and 50 ng/mL, Levels under 20 ng/mL are inadequate for bone health and levels over 50 ng/mL are associated with potential adverse effects, such as an increased risk of developing kidney stones.

Researchers conducted a year-long study to assess the effect of weight loss on vitamin D. They assigned 439 overweight or obese postmenopausal women to one of four regimens: exercise only, diet only, exercise plus diet and no intervention. About 70 percent of the participants had less-than-optimal levels of vitamin D when the study began; at baseline, the mean blood level of vitamin D among the study participants was 22.5 ng/mL. In addition, 12 percent of the women were at risk of vitamin D deficiency (blood levels of less than 12 ng/mL).

Women who lost up to 10 percent of their body weight (10 to 20 pounds) through diet and exercise saw modest increases in vitamin D, those levels were roughly three times higher in women who dropped more than 15 percent of their body weight, regardless of dietary intake of the nutrient.

The researchers were surprised at the effect of weight loss greater than 15 percent on blood vitamin D levels. It appears that the relationship between weight loss and blood vitamin D is not linear but goes up dramatically with more weight loss. It is thought that obese and overweight people have lower levels of vitamin D because the nutrient is stored in fat deposits. During weight loss, it is suspected that the vitamin D that is trapped in the fat tissue is released into the blood and available for use throughout the body.

The findings suggest the greater the weight loss, the more meaningful the surge in vitamin D levels. However, the researchers noted that the degree to which vitamin D is available to the body during and after weight loss remains unclear. They also cautioned that more targeted research is needed to understand any link between vitamin D deficiency and chronic disease.

via Weight loss in the obese boosts vitamin D levels.

A long-awaited report from a panel of independent scientists recommends tripling the amount of vitamin D most Americans should take and small increases in calcium levels for children to build and maintain strong bones, but some specialists warned that the recommendations were flawed.

The Institute of Medicine panel’s findings, being released today, carry considerable weight — government agencies rely on the recommendations to set food policy, everything from product labeling to requirements for school lunch programs. And a raft of health-related organizations, such as the National Osteoporosis Foundation, use the guidelines to set their policies for nutrient recommendations for specific groups of patients.

Some research has suggested that consumption of even higher amounts of vitamin D could protect against heart disease and various cancers, but the panel said that after scrutinizing nearly a thousand studies, it could not find sufficient evidence that more vitamin D would be beneficial and safe.

It said the best evidence it could find showed that the new recommended levels of vitamin D and calcium were the optimum ones for building strong bones without risking harmful side effects.

“More is not necessarily better for vitamin D,’’ said panel member Dr. JoAnn Manson, a Harvard Medical School professor and chief of preventative medicine at Brigham and Women’s Hospital.

“We need to consider the lessons of other nutrients, such as vitamin E and beta-carotene, as cautionary tales,’’ Manson said, referring to earlier popular wisdom that those nutrients held promise as weapons against illnesses. “Randomized clinical trials did not find benefit and suggested harm.’’

For vitamin D, the panel tripled the daily recommended allowance from 200 international units to 600 units for people aged 1 to 50. It also recommended that amount for people up to age 70. Previously, the amount for that group had been 400 units. Over age 70, it recommended 800 units.

The guideline changes for calcium were less dramatic: The panel suggested 700 milligrams daily for children 1 to 3 years old, up from 500 now; and 1,000 mg. for 4- to 8-year-olds, up from 800. For most adults, the daily intake remains at 1,000 mg. It kept the recommended 1,200 mg. for women over 50, but reduced the amount for men that age to 1,000.

The guidelines have not been updated by the institute since 1997, and in the interim various organizations have issued their own recommendations, producing confusing and sometimes conflicting advice for consumers.

The 14-member panel also concluded that most laboratories are setting the bar too high when they measure whether patients have adequate vitamin D in their bloodstream, a test that then prompts physicians to prescribe higher doses.

“We are not making any blanket statements that if your doctor recommends high dose supplements that you should stop taking them,’’ Manson said.
Instead, she said, the panel’s aim was to spur consensus among labs to create more uniform, lower guidelines.

Other specialists who were invited by the panel to review its work said its recommendations for adequate vitamin D levels fell short, and that older patients especially would lose out.

Dr. Bess Dawson-Hughes, director of the Bone Metabolism Laboratory at Tufts University, said that the panel’s recommendations for how much vitamin D patients over age 60 should have in their blood stream was too low.

She said her studies and those of other researchers have shown that older patients need higher levels of D in their blood stream than the panel recommended.

“The older population will have fewer fractures and falls, across the board, if they have higher (blood) levels,’’ said Hughes, who was a member of the 1997 panel that last updated the recommendations.

Otherwise, she said, she found the recommendations generally on target.

But Dr. Walter Willett, chair of the nutrition department at Harvard’s School of Public Health, said the panel’s recommendations for vitamin D were too low and its recommendations for calcium too high.

He said the panel’s conclusion that the “majority of Americans’’ are receiving adequate amounts of vitamin D is “flawed.’’ He said strong evidence indicates that most adults need nearly twice the amount of vitamin D that the panel recommended — at least 1,000 units a day, not 600. He said there is strong evidence that higher levels of vitamin D not only reduce the risk of fractures in older adults, they also reduce the risk for colon cancer.

Willett also said that other international panels of scientists, including the World Health Organization, recommend half the amount of calcium for adults, suggesting 500 milligrams daily, not 1,000. He said strong evidence suggested that elevated calcium levels increase the risk of fatal prostate cancer, and possibly ovarian cancer. He said that calcium is added to so many foods, such as orange juice, that Americans may unwittingly be consuming far too much calcium.

“These guidelines get translated to dietary policy . . . how many glasses of milk a day consumers should have . . . and schools have to conform to them, so they have a big downstream impact,’’ Willett said.

The federal departments of Health and Human Services and Agriculture are finalizing new daily guidelines, expected out by year’s end, on a broad array of nutrients.

A spokesman for the Agriculture Department said it is still studying the institute’s calcium and vitamin D recommendations.

A spokeswoman for the National Osteoporosis Foundation said her organization had not yet decided whether to change its recommendations for vitamin D intake. The foundation has recommended substantially higher levels of vitamin D for adults over 50 — as much as 1,000 units — than was included in the institute’s new guidelines.

via Calcium, vitamin D changes suggested – The Boston Globe.

Vitamin D promises to be the most talked-about and written-about supplement of the decade. While studies continue to refine optimal blood levels and recommended dietary amounts, the fact remains that a huge part of the population — from robust newborns to the frail elderly, and many others in between — are deficient in this essential nutrient.

If the findings of existing clinical trials hold up in future research, the potential consequences of this deficiency are likely to go far beyond inadequate bone development and excessive bone loss that can result in falls and fractures. Every tissue in the body, including the brain, heart, muscles and immune system, has receptors for vitamin D, meaning that this nutrient is needed at proper levels for these tissues to function well.

Studies indicate that the effects of a vitamin D deficiencyinclude an elevated risk of developing (and dying from) cancers of the colon, breast and prostate; high blood pressure and cardiovascular disease; osteoarthritis; and immune-system abnormalities that can result in infections and autoimmune disorders like multiple sclerosis, Type 1 diabetes and rheumatoid arthritis.

Most people in the modern world have lifestyles that prevent them from acquiring the levels of vitamin D that evolution intended us to have. The sun’s ultraviolet-B rays absorbed through the skin are the body’s main source of this nutrient. Early humans evolved near the equator, where sun exposure is intense year round, and minimally clothed people spent most of the day outdoors.

“As a species, we do not get as much sun exposure as we used to, and dietary sources of vitamin D are minimal,” Dr. Edward Giovannucci, nutrition researcher at the Harvard School of Public Health, wrote in The Archives of Internal Medicine. Previtamin D forms in sun-exposed skin, and 10 to 15 percent of the previtamin is immediately converted to vitamin D, the form found in supplements. Vitamin D, in turn, is changed in the liver to 25-hydroxyvitamin D, the main circulating form. Finally, the kidneys convert 25-hydroxyvitamin D into the nutrient’s biologically active form, 1,25-dihydroxyvitamin D, also known as vitamin D hormone.

A person’s vitamin D level is measured in the blood as 25-hydroxyvitamin D, considered the best indicator of sufficiency. A recent study showed that maximum bone density is achieved when the blood serum level of 25-hydroxyvitamin D reaches 40 nanograms per milliliter or more.

“Throughout most of human evolution,” Dr. Giovannucci wrote, “when the vitamin D system was developing, the ‘natural’ level of 25-hydroxyvitamin D was probably around 50 nanograms per milliliter or higher. In modern societies, few people attain such high levels.”

A Common Deficiency

Although more foods today are supplemented with vitamin D, experts say it is rarely possible to consume adequate amounts through foods. The main dietary sources are wild-caught oily fish (salmon, mackerel, bluefish, and canned tuna) and fortified milk and baby formula, cereal and orange juice.

People in colder regions form their year’s supply of natural vitamin D in summer, when ultraviolet-B rays are most direct. But the less sun exposure, the darker a person’s skin and the more sunscreen used, the less previtamin D is formed and the lower the serum levels of the vitamin. People who are sun-phobic, babies who are exclusively breast-fed, the elderly and those living in nursing homes are particularly at risk of a serious vitamin D deficiency.

Dr. Michael Holick of Boston University, a leading expert on vitamin D and author of “The Vitamin D Solution” (Penguin Press, 2010), said in an interview, “We want everyone to be above 30 nanograms per milliliter, but currently in the United States, Caucasians average 18 to 22 nanograms and African-Americans average 13 to 15 nanograms.” African-American women are 10 times as likely to have levels at or below 15 nanograms as white women, the third National Health and Nutrition Examination Survey found.

Such low levels could account for the high incidence of several chronic diseases in this country, Dr. Holick maintains. For example, he said, in the Northeast, where sun exposure is reduced and vitamin D levels consequently are lower, cancer rates are higher than in the South. Likewise, rates of high blood pressure, heart disease, and prostate cancer are higher among dark-skinned Americans than among whites.

The rising incidence of Type 1 diabetes may be due, in part, to the current practice of protecting the young from sun exposure. When newborn infants in Finland were given 2,000 international units a day, Type 1 diabetes fell by 88 percent, Dr. Holick said.

The current recommended intake of vitamin D, established by the Institute of Medicine, is 200 I.U. a day from birth to age 50 (including pregnant women); 400 for adults aged 50 to 70; and 600 for those older than 70. While a revision upward of these amounts is in the works, most experts expect it will err on the low side. Dr. Holick, among others, recommends a daily supplement of 1,000 to 2,000 units for all sun-deprived individuals, pregnant and lactating women, and adults older than 50. The American Academy of Pediatrics recommends that breast-fed infants receive a daily supplement of 400 units until they are weaned and consuming a quart or more each day of fortified milk or formula.

Given appropriate sun exposure in summer, it is possible to meet the body’s yearlong need for vitamin D. But so many factors influence the rate of vitamin D formation in skin that it is difficult to establish a universal public health recommendation. Asked for a general recommendation, Dr. Holick suggests going outside in summer unprotected by sunscreen (except for the face, which should always be protected) wearing minimal clothing from 10 a.m. to 3 p.m. two or three times a week for 5 to 10 minutes.

Slathering skin with sunscreen with an SPF of 30 will reduce exposure to ultraviolet-B rays by 95 to 98 percent. But if you make enough vitamin D in your skin in summer, it can meet the body’s needs for the rest of the year, Dr. Holick said.

Can You Get Too Much?

If acquired naturally through skin, the body’s supply of vitamin D has a built-in cutoff. When enough is made, further exposure to sunlight will destroy any excess. Not so when the source is an ingested supplement, which goes directly to the liver.

Symptoms of vitamin D toxicity include nausea, vomiting, poor appetite, constipation, weakness and weight loss, as well as dangerous amounts of calcium that can result inkidney stones, confusion and abnormal heart rhythms.

But both Dr. Giovannucci and Dr. Holick say it is very hard to reach such toxic levels. Healthy adults have taken 10,000 I.U. a day for six months or longer with no adverse effects. People with a serious vitamin D deficiency are often prescribed weekly doses of 50,000 units until the problem is corrected. To minimize the risk of any long-term toxicity, these experts recommend that adults take a daily supplement of 1,000 to 2,000 units.

Personal Health – What Do You Lack? Probably Vitamin D – NYTimes.com.

WHEN I stock up on ibuprofen (my painkiller of choice), I typically buy a 500-count bottle of a store brand like Kirkland or Rite Aid. After all, ibuprofen is ibuprofen. Each pill costs me about 3 cents — or only one-third the cost of 9-cent Advil.

Yet, when it comes to vitamins — which I take only when I feel run down — I turn to name brands like Centrum or Nature Made. My thinking has been: Why mess around with quality when it comes to the essential ABCs?

But now that I’ve done some research, I might soon change my vitamin-buying ways. Read on to find out why.

Americans love vitamins. About half of adults take a daily multivitamin, according to industry data. And according to some theories, the economic downturn has inspired them to fortify themselves by swallowing more.

Sales over the last decade had been growing by about 4 percent annually. But this year, as more people are taking their health into their own hands, perhaps hoping to stave off doctor bills, vitamin sales are expected to grow by 8 percent to a total of $9.2 billion, according to Nutrition Business Journal, a market researcher and publisher.

About 42 percent of shoppers purchase their vitamins at natural and specialty retail outlets, like GNC and Whole Foods, according to the journal, while only 23 percent take the discount approach and buy their bottles at supermarkets and club stores. The other 35 percent buy through mail order or from a health care provider.

Of course, it’s controversial whether we should be taking vitamins at all. Recent studies have indicated that taking a multivitamin won’t protect you from heart disease or cancer. And experts maintain that if you eat well, you don’t need vitamin supplements.

“The evidence shows that a healthy diet and exercise are the best way to ward off disease; a vitamin cannot replace those benefits,” says Eric Rimm, associate professor of epidemiology and nutrition at the Harvard School of Public Health.

But what if you don’t eat well or are chronically stressed out? Then, Professor Rimm says, there may be some benefit from taking a multivitamin. “Certain subgroups, including women of child-bearing age attempting to get pregnant, may need specific supplements, like folic acid and omega-3,” he added.

As for the matter of cost: If you take only a daily multivitamin mainly as a medicalinsurance policy, it certainly won’t hurt your health — as long as you do not already eat a lot of fortified food. And it could help. But it will require spending some money. And if you take a multivitamin and a few individual vitamins and minerals, it’s even more worth your while to make sure you’re not paying more than you need to.

Here’s how to get the most vitamin for the least money.

USE ONLY WHAT YOU NEED Popping too many vitamin pills is not only a waste of money but can be bad for your health. Talk to your doctor about what added vitamins or minerals you might require; you can ask for a blood test to learn what you might be lacking.

For example, if you don’t get enough vitamin D — many people who live in the northern states or who wear sunscreen everyday are low on this crucial vitamin — then buy just a D supplement. Standard multivitamins will probably not have the levels of D you require (many doctors suggest taking 1,000 to 2,000 international units a day).

If your doctor recommends a specific supplement, like omega-3, ask in what form you should be taking it.

FIND A REPUTABLE SOURCE Vitamins and minerals are commodity items, and every manufacturer has access to the same ingredients. For that reason, researchers and scientists say paying more for a name brand won’t necessarily buy you better vitamins.

“When we measure levels of vitamins in the blood, we find the levels are the same whether the person was taking a generic brand or a name brand,” says Dr. Rimm, who has been studying the effects of vitamins for 20 years.

That said, don’t be too cheap. Purchase your vitamins from well-known retailers that do a brisk business and restock frequently, whether that’s Costco or Drugstore.com. Vitamins lose their potency over time and must be stored at, or below, room temperature. If bottles are sitting on a shelf in warm room or in direct sunlight, they may degrade even before their expiration date.

PRICE MAY NOT MEAN QUALITY While the Food and Drug Administrationregulates vitamins as part of the nutritional supplement industry, it does not test them before they are put on the shelves. The F.D.A. places the responsibility on the manufacturer to ensure that its dietary supplement products are safe before they are marketed. All of which means that no matter what the price, quality is not assured.

ConsumerLab.com, a company based in White Plains that tests hundreds of vitamins each year, finds that 30 percent of multivitamins have a quality problem: the pills might have more or less of a stated ingredient, or they might not dissolve properly.

“We haven’t found any brand with a broad product line that makes every product well,” says Dr. Tod Cooperman, president of the company.

Taking exception to such assertions is the vitamin industry’s trade group, the Council for Responsible Nutrition. In response to questions, the council released a statement from Andrew Shao, a vice president for scientific and regulatory affairs.

Mr. Shao said that the F.D.A. allowed for “a reasonable amount of variation” — which he characterized as up to 15 percent more of an ingredient than the label might indicate. Mr. Shao said that manufacturers frequently add slightly more of an ingredient to ensure that the amount is at least at the level claimed on the label as the product nears the end of its shelf life.

In any case, ConsumerLab.com says it has found a few patterns that consumers may find helpful. Products sold by vitamin chains tend to be more reliable than drugstore brands, and Wal-Mart and Costco’s vitamin lines are usually worth considering. In a recent test of multivitamins, ConsumerLab.com found that Equate-Mature Multivitamin 50+ sold by Wal-Mart was just as good as the name brand Centrum Silver, but at less than a nickel a day is half the price.

Puritan’s Pride, a catalog and online retailer, also has very good prices, and Dr. Cooperman says that its products are generally good.

Curious consumers can subscribe to ConsumerLab.com for $30 a year and learn how other supplement brands fare in the lab’s tests.

CERTIFICATION SYMBOLS One quality check you can make, although it is not a perfect screening, is to see whether a product is certified by one of several nonprofit organizations that check supplements for purity and quality.

The two most commonly used groups are the United States Pharmacopeia (www.usp.org) and NSF International (www.nsf.org), according to Mr. Shao. Manufacturers voluntarily submit a product for review and, if it passes, the product can bear an approval seal, such as USP or NSF. Because the process is voluntary, Mr. Shao points out, the absence of the seal does not necessarily mean the product is of poor quality.

But at least the seal should mean you know what you’re getting. And with vitamins, anything beyond that simple assurance may not be worth paying for.

Patient Money – When Buying Vitamins, Know What’s Worth Paying For – NYTimes.com.

>> The original study can be found at PNAS

That is the message of a surprising new look at the body’s reaction to exercise, reported on Monday by researchers in Germany and Boston.

Exercise is known to have many beneficial effects on health, including on the body’s sensitivity to insulin. “Get more exercise” is often among the first recommendations given by doctors to people at risk of diabetes.

But exercise makes the muscle cells metabolize glucose, by combining its carbon atoms with oxygen and extracting the energy that is released. In the process, some highly reactive oxygen molecules escape and make chemical attacks on anything in sight.

These reactive oxygen compounds are known to damage the body’s tissues. The amount of oxidative damage increases with age, and according to one theory of aging it is a major cause of the body’s decline.

The body has its own defense system for combating oxidative damage, but it does not always do enough. So antioxidants, which mop up the reactive oxygen compounds, may seem like a logical solution.

The researchers, led by Dr. Michael Ristow, a nutritionist at the University of Jena in Germany, tested this proposition by having young men exercise, giving half of them moderate doses of vitamins C and E and measuring sensitivity to insulin as well as indicators of the body’s natural defenses to oxidative damage.

The Jena team found that in the group taking the vitamins there was no improvement in insulin sensitivity and almost no activation of the body’s natural defense mechanism against oxidative damage.

The reason, they suggest, is that the reactive oxygen compounds, inevitable byproducts of exercise, are a natural trigger for both of these responses. The vitamins, by efficiently destroying the reactive oxygen, short-circuit the body’s natural response to exercise.

“If you exercise to promote health, you shouldn’t take large amounts of antioxidants,” Dr. Ristow said. A second message of the study, he said, “is that antioxidants in general cause certain effects that inhibit otherwise positive effects of exercise, dieting and other interventions.” The findings appear in this week’s issue of The Proceedings of the National Academy of Sciences.

The effect of vitamins on exercise and glucose metabolism “is really quite significant,” said Dr. C. Ronald Kahn of the Joslin Diabetes Center in Boston, a co-author of the report. “If people are trying to exercise, this is blocking the effects of insulin on the metabolic response.”

The advice does not apply to fruits and vegetables, Dr. Ristow said; even though they are high in antioxidants, the many other substances they contain presumably outweigh any negative effect.

Dr. Kahn said it might be that reactive oxygen is beneficial in small doses, because it touches off the body’s natural defense system, but harmful in higher doses.

Andrew Shao of the Council for Responsible Nutrition, a trade association of dietary supplement makers, said the new study was well designed but was just one bit of evidence in a complex issue. Most available evidence points to the opposite conclusion, that antioxidants benefit health by reducing oxidative stress, he said.

“I wouldn’t change recommendations for anyone based on one study,” he said. “This is one small piece of the puzzle.”

Vitamins Found to Curb Exercise Benefits – NYTimes.com.

As studies beginning in the 1980s started showing that folic acid could also help prevent some cancers, it started to seem like a wonder-vitamin. Now, however, folic acid’s heyday may be over. New studies suggest that getting too much folic acid might fuel certain cancers in some people. 

Folic acid might be losing its sheen – Los Angeles Times.