Vitamin Information Center

Large sectors of the U.S. population are deficient in vitamin B6, according to a new study conducted by researchers from Tufts University and published in the American Journal of Clinical Nutrition.

The researchers warned that signs of deficiency emerged even among those meeting or exceeding the recommended dietary intake, and among those taking supplements.

“Across the study population, we noticed participants with inadequate vitamin B6 status even though they reported consuming more than the Recommended Daily Allowance of vitamin B6, which is less than two milligrams per day,” researcher Martha Savaria Morris said.

The Recommended Daily Allowance (RDA) for vitamin B6 is 1.3 milligrams per day for people between the ages of 19 and 50, 1.5 milligrams per day for women over the age of 50 and 1.7 milligrams per day for men over 50.

Researchers analyzed blood samples from 7,822 people of all ages, down to one year old, who participated in the 20043-04 National Health and Nutrition Examination Survey. They measured blood levels of pyridoxal 5′- phosphate (PLP), the biologically active form of the vitamin.

Eleven percent of those taking vitamin B6 supplements had PLP levels indicating deficiency, while 25 percent of those not taking supplements were vitamin deficient.

Male smokers, non-Hispanic African-American men and people of both sexes over the age of 65 were more likely to be vitamin B6 deficient. Women of childbearing age were also at increased risk for deficiency, especially those who had a history of oral contraceptive use.

Among women who did not take vitamin B6 supplements but did take oral contraceptives, 75 percent came up deficient in the vitamin.

The scientists called for more research into this connection, noting that it is possible that vitamin B6 is stored in a different way in women who take oral contraceptives, thus making blood concentration a less useful marker.

Foods rich in vitamin B6 include nuts, vegetables, whole grains and meats.

Sources for this story include: www.foodnavigator-usa.com.

A diet lacking in B vitamins may result in cognitive problems, new findings suggest.

Vitamin B deficiency could result in cognitive impairment, according to new research published in Proceedings of the National Academy of Sciences.

Researchers from the Jean Mayer USDA Human Nutrition Research Centre on Ageing (HNRCA) at Tufts University found that mice given a diet which was deficient in three B-vitamins showed cognitive dysfunction as well as reductions in both brain capillary length and density.

The mice deficient in B-vitamins took longer to perform tasks such as navigating a water maze.

Dr Aron Troen, lead author of the study and assistant professor at Tufts University’s Friedman School of Nutrition Science and Policy, commented: “Mice fed a diet deficient in folate and vitamins B12 and B6 demonstrated significant deficits in spatial learning and memory compared with normal mice.”

Meanwhile, a separate study has suggested that regular walking could have a positive effect for people with memory problems.

A study published in the Journal of the American Medical Association suggested that individuals aged over 50 who go walking for over two-and-a-half hours a week can see significant improvements in memory problems

Research reports keep rolling in on the importance of vitamin D in our diet-beyond its familiar role in helping us to build strong bones. Here are some of the findings: Periodontal disease, in a dental study of 6,700 people from 13 to 90, the gums of patients with higher blood levels of vitamin D were 20 percent less likely to bleed. “The evidence on gingivitis and tooth loss suggests that vitamin D influences oral health by decreasing inflammation,” said Bess Dawson-Hughes, director of the Bone Metabolism Lab at the Human Nutrition Research Center on Aging at Tufts University.

Cancer. Studies by Reinhold Vieth at the University of Toronto have reported a substantial reduction in the rates of colon cancer as blood levels of vitamin D went up. Dr. Vieth suggests that vitamin D inhibits a mechanism by which cancer cells spread or it may boost the function of blood vessels or the immune system.

Diabetes. A number of studies have found that people with higher blood levels of vitamin D had a lower risk of diabetes than people with lower levels. Researchers have suggested that vitamin D seems to influence responsiveness to insulin.

Fitness. A study at the Wake Forest University School of Medicine found that people with low blood levels of vitamin D scored from 5 to 10 percent lower on tests measuring grip strength, balance and walking speed than those who had higher levels. Apparently vitamin D helps build and repair muscles as well as bones.

Longevity. People who take vitamin D supplements may also live longer, according to Sara Gandini, Ph.D., of the European Institute of Oncology in Italy, and Philippe Autier, M.D., of the International Agency for Research on Cancer in France. “The intake of ordinary doses of vitamin D supplements seems to be associated with decreases in total mortality rates,” they reported.

“The results are remarkable,” according to Edward Giovannucci, M.D., ScD., of the Harvard School of Public Health, in an editorial on vitamin D research in the Archives of Internal Medicine.

What to do. Adults should try to get 800 international units (IU) daily of vitamin D-or 1000 IUs a day if you are 70 or older. The average U.S. adult intake of vitamin D is 230 IUs daily, according to a study reported in the journal Nutrition Reviews. Vitamin D is available from sunlight, of course, and from foods such as fatty fish, eggs, fortified milk and fortified cereals as well as supplements.

-Sources: Bottom Line Health, CSPI Nutrition Action Letter, and Tufts University Health & Nutrition Letter

You’ve been told for years that popping a multivitamin every day might help you live longer. But the daily-multi habit has been getting a bit of bad press lately.

First, ConsumerLab.com, a watchdog of the supplement industry, found that more than half of the 21 multis it tested had too much (or too little) of certain vitamins—or had been contaminated with dangerous substances like lead. Then a controversial paper from researchers in Denmark and other European countries, published in the Journal of the American Medical Association, made the claim that taking vitamins may actually shorten your life.

What’s the real story? Health talked to leading nutrition experts at Harvard and Tufts universities to find out and to get some answers on this and other confusing info about vitamins.

Are multivitamins safe?
Vitamins have been recommended for years because they help you get key nutrients if your diet’s low on fruits and veggies—and may even help prevent cancer and heart disease. And it’s unlikely that one critical paper (speculating that vitamin supplements might upset your body’s natural healing process and boost your risk of death) will change that.

Longtime vitamin experts at Tufts University and the Linus Pauling Institute at Oregon State University continue to say multis aren’t dangerous and the paper’s findings are wrong. The paper analyzed previous studies, including many with people who were sick before taking vitamins, so there’s a good chance vitamins weren’t responsible for shortening their lives. Experts say the paper also ignored two major studies that found vitamins reduced the risk of death.

At the same time, the study from ConsumerLab.com shows that you can’t assume just any vitamin is safe. Because there are no uniform manufacturing rules for supplements, a multi may not contain what the bottle claims, could be contaminated with something from the manufacturing plant, or might have tainted ingredients.

Your best bet: Avoid the vitamins singled out by ConsumerLab.com (see “11 Multis to Avoid”), and stick with mainstream names like Centrum Silver and One-A-Day Women’s, which were found to be free of impurities and accurately labeled. Also, check vitamin bottles for the United States Pharmacopoeia (USP), NSF International (NSF), or ConsumerLab.com (CL) seals. The USP and NSF are nonprofit groups that verify whether companies offer contamination-free products and use good manufacturing practices. Not every brand has the seals—some don’t want to submit to testing—but those that do (Kirkland and Nature Made carry the USP seal, for instance) are reliable.

How much should I spend to get the biggest benefits?
Price isn’t a sign of quality. In fact, some of the priciest vitamins—like The Greatest Vitamin in the World and Eniva Vibe, which cost more than $39.95 per bottle—failed the Consumer Lab.com tests. A mainstream brand like One-A-Day Women’s is $8.99 for a bottle of 100 tablets at about 9 cents per day.

How do I find the right multi for me?
In your childbearing years, make sure your multi has 400 micrograms (mcg) of folic acid, which helps make and maintain new cells. And pregnant women should take a vitamin with 600 mcg of folic acid daily; this nutrient also reduces the incidence of neural tube birth defects like spina bifida.

A premenopausal woman should look for a multivitamin with iron to replace the iron lost during menstruation. Menopausal women should go without the iron. “Too much iron may raise the risk of heart disease,” says Meir Stampfer, PhD, professor of nutrition and epidemiology at Harvard School of Public Health.

If you’re taking a prescription, check with your doctor about risky interactions. (Vitamin E, for instance, may be a problem if you’re taking a blood thinner.) If you’re a cancer patient, you should ask your doctor about risks before taking vitamins. “Cancer cells need vitamins to grow, too,” Stampfer says. Plus, some vitamins can interfere with chemotherapy.

What’s the best way to avoid that queasy feeling after taking a multi?
“Consider switching brands,” Stampfer suggests. Trial and error is the best way to determine which brands won’t break down poorly in your stomach and lead to irritation. Also, take your multi with food because your body needs some fat (or lipids) to absorb some of the individual vitamins. The delivery method (pill, liquid, gummy bear) makes no difference. But vitamins in liquid form may degrade more quickly on the shelf.

How much of each vitamin should my multi have?
The amount per serving numbers on the label should match the government’s Dietary Reference Intakes (DRI). It’s OK if they’re higher as long as they don’t exceed the tolerable upper limit (UL). (To find the DRIs and ULs, While most vitamins are listed in milligrams (mg) or micrograms (mcg), the label may use IUs (international units) for vitamins A, D, and E. The DRIs are 2,300 IUs for vitamin A, 200 for D, and 22 for E. What about the label’s % Daily Value column? Look at it with a skeptical eye: Those numbers haven’t been updated since 1968.