Folic Acid, Multivitamins During Pregnancy May Cut ASD Risk


Israeli researchers caution that ‘the effect of confounding was notable.

Folic acid and multivitamins both before and during pregnancy seemed to reduce the risk of autism spectrum disorder (ASD) in children, a large Israeli study found.

Compared with women with no exposure to folic acid and/or multivitamin supplementation, women who took folic acid and/or these vitamin supplements during pregnancy had a significantly reduced risk of offspring with ASD (adjusted RR 0.27, 95% CI 0.22-0.33, P<0.001), with similar results seen among women who took these supplements before pregnancy (adjusted RR 0.39, 95% CI 0.30-0.50, P<0.001), reported Stephen Z. Levine, PhD, of University of Haifa in Israel, and colleagues.

Similar results were found when the effects of folic acid and multivitamin supplements were examined individually, the authors wrote in JAMA Psychiatry.

But the authors outlined a number of limitations to their findings, namely that “the effect of confounding was notable,” and expressed reservations about residual confounding. They also noted the small size of their study, and pointed out potential misclassification of exposure, or unrecorded use of supplements, such as a mother using over-the-counter supplements. Finally, they pointed out that there was no information about the mothers’ whole-blood folate levels and that the registry could not distinguish between multivitamins with and without folic acid.

While they noted that vitamin deficiency has inconsistent links with cognitive functioning, previous epidemiological studies found conflicting results when examining multivitamins or folic acid in pregnancy on the risk of ASD in children.

This case-cohort study examined data from certain healthcare registers in Israel on children born from January 2003 to December 2007. A diagnosis of ASD was performed by a physician after evaluation by a team of experts.

Overall, there were 572 children out of 43,500 in the study (1.3%) with a diagnosis of ASD. The study was comprised of 22,090 girls and 23,210 boys, with a mean age of 10 years at the end of follow-up.

In addition to the effects of folic acid and/or multivitamin supplements, Levine’s group looked at the individual effects of maternal exposure to folic acid and multivitamin supplements compared to unexposed mothers and found similar results:

  • Folic acid during pregnancy: adjusted RR 0.32 (95% CI 0.26-0.41, P<0.001)
  • Folic acid before pregnancy: adjusted RR 0.56 (95% CI 0.42-0.74, P=0.001)
  • Multi-vitamin supplements during pregnancy: adjusted RR 0.35 (95% CI 0.28-0.44, P<0.001)
  • Multi-vitamin supplements before pregnancy: adjusted RR 0.36 (95% CI 0.24-0.52, P<0.001)

Sensitivity analyses that looked at different time periods of exposure or potential additional confounders generally did not lessen these associations, the authors said. They did note that for offspring whose parents had a psychiatric condition, folic acid supplementation did not significantly reduce the risk of ASD.

“This finding may reflect noncompliance, higher rates of vitamin deficiency, or poor diet among persons with psychiatric conditions,” Levine’s group wrote.

Most vitamins are useless, but here are the ones you should take.


Forget multivitamins.

 It seems like simple, obvious advice: eat your vegetables, get some exercise, and – of course – take your vitamins. Or not. Decades of research has failed to find any substantial evidence that vitamins and supplements do any significant good.

In fact, recent studies skew in the opposite direction, having found that certain vitamins may be bad for you. Several have been linked with an increase in certain cancers, for example, while others have been tied to a rise in the risk of kidney stones.

 And a large new study out Wednesday suggests that despite this growing knowledge, Americans’ pill-popping habits have stayed basically the same over the last decade.

So here are the vitamins and supplements you should take – and the ones you should avoid:

Multivitamins: Skip them – you get everything you need with a balanced diet.

For decades, it was assumed that multivitamins were critical to overall health. Vitamin C to “boost your immune system”, Vitamin A to protect your vision, Vitamin B to keep you energized.

Not only do you already get these ingredients from the food you eat, but studies suggest that consuming them in excess can actually cause harm.

A large 2011 study of close to 39,000 older women over 25 years found that women who took them in the long term actually had a higher overall risk of death than those who did not.

Vitamin D: Take it – it helps keep your bones strong and it’s hard to get from food.

Vitamin D isn’t present in most of the foods we eat, but it’s a critical ingredient that keeps our bones strong by helping us absorb calcium.

Getting sunlight helps our bodies produce it as well, but it can be tough to get enough in the winter. Several recent study reviews have found that people who took Vitamin D supplements daily lived longer, on average, than those who didn’t.

Antioxidants: Skip them – an excess of these has been linked to an increased risk of certain cancers, and you can eat berries instead.

Vitamins A, C, and E are antioxidants found in plentiful form in many fruits – especially berries – and veggies, and they’ve been touted for their alleged ability to protect against cancer.

But studies suggest that when taken in excess, antioxidants can actually be harmful. A large, long-term study of male smokers found that those who regularly took Vitamin A were more likely to get lung cancer than those who didn’t.

And a 2007 review of trials of several different types of antioxidant supplements put it this way: “Treatment with beta carotene, vitamin A, and vitamin E may increase mortality.”

Vitamin C: Skip it – it probably won’t help you get over your cold, and you can eat citrus fruits instead.

The Vitamin C hype – which started with a suggestion from chemist Linus Pauling made in the 1970s and has peaked with Airborne and Emergen-C – is just that: hype.

Study after study has shown that Vitamin C does little to nothing to prevent the common cold. Plus, megadoses of 2,000 milligrams or more can raise your risk of painful kidney stones.

So get your Vitamin C from your food instead. Strawberries are packed with the nutrient.

Vitamin B3: Skip it and eat salmon, tuna, or beets instead.

For years, Vitamin B3 was promoted to treat everything from Alzheimer’s to heart disease. But recent studies have called for an end to the over-prescription of the nutrient.

large 2014 study of more than 25,000 people with heart disease found that putting people on long-acting doses of Vitamin B3 to raise their levels of ‘good’, or HDL, cholesterol didn’t reduce the incidence of heart attacks, strokes, or deaths.

Plus, people in the study who took the B3 supplements were more likely than those taking a placebo to develop infections, liver problems, and internal bleeding.

Probiotics: Skip them – the science isn’t advanced enough yet for them to have a significant benefit, and you can eat yogurt instead.

Probiotics – pricey bacterial supplements that can cost upward of $1 per pill but are found naturally in smaller amounts in yogurt and other fermented foods – have become a big business with a market of roughly US $23.1 billion in 2012.

The idea behind them is simple: Support the trillions of bacteria blossoming in our gut which we know play a crucial role in regulating our health.

But putting that idea into actual practice has been a bit more complicated. So far, the effects of probiotics have been all over the map. Sometimes they help, sometimes they don’t. So rather than shelling out for a pill that promises to be a cure-all, snack on a parfait.

Zinc: Take it – it’s one of the only ingredients linked to shortening a cold.

Unlike Vitamin C, which studies have found likely does nothing to prevent or treat the common cold, zinc may actually be worth it. The mineral seems to interfere with the replication of rhinoviruses, the bugs that cause the common cold.

In a 2011 review of studies of people who’d recently gotten sick, researchers looked at those who’d started taking zinc and compared them with those who just took a placebo. The ones on the zinc had shorter colds and less severe symptoms.

Vitamin E: Skip it – an excess has been linked to an increased risk of certain cancers, and you can eat spinach instead.

The antioxidant Vitamin E was popularized for its alleged ability to protect against cancer. But a large 2011 study of close to 36,000 men found that the risk of prostate cancer actually increased among the men taking Vitamin E compared to the men taking a placebo.

And a 2005 study linked high doses of Vitamin E with an overall higher risk of death. So if you’re looking for more Vitamin E, make yourself a fresh spinach salad and skip the pill. Dark greens like spinach are rich with this stuff.

Folic acid: Take it if you’re pregnant, or if you might want to get pregnant.

Folic acid is a B vitamin which our bodies use to make new cells.

The National Institutes of Health recommends that women who are currently pregnant or who want to get pregnant take 400 micrograms of folic acid daily because their bodies demand more of this key nutrient when they are carrying a growing fetus.

Additionally, several large studies have linked folic acid supplementation before and during pregnancy with decreased rates of neural-tube defects, serious and life-threatening birth defects of the baby’s brain, spine, or spinal cord.

Should Aging Adults Take Multivitamins?


Changes associated with normal aging and age-related diseases can impact the nutritional intake of older adults, which in turn affects aspects of health ranging from cardiovascular function to cognition. As the years pass, many may wonder whether they should take a daily multivitamin to fill any gaps in their diet.

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Take Note

  • Numerous studies looking at the effects of multivitamins on overall health as well as on specific health parameters have generated conflicting results.
  • The only long-term, large-scale randomized clinical trial on multivitamin use, conducted just in men, found modest but significant reductions in cancer and cataracts, but not cardiovascular disease or cognitive decline. Results from randomized clinical trials indicate no survival benefit to multivitamin use.
  • Multivitamins are safe products that can provide clear benefits for those who have, or are at high risk for, nutritional deficiencies.

“For very healthy patients with a great diet, a multivitamin may not be necessary; however, a simple multivitamin is unlikely to hurt either, so it becomes a personal choice,” said Katherine Tucker, PhD, a Professor of Nutritional Epidemiology in the Department of Clinical Laboratory & Nutritional Sciences at UMass Lowell.

“As nutrient inadequacies are more common with aging, though, a multivitamin supplement may be useful for many individuals, particularly if the diet is not adequate in nutrient quality.”

Multiple factors come into play when considering the nutritional needs of older and elderly adults—for example, their specific health conditions, activity level, caloric requirements, and ability to access and prepare food (not to mention their personal food preferences) will shift over time and have varying effects on their dietary intake. Tucker noted that aging is often associated with a decreased sense of smell and appetite that may lead to inadequate nutrient intake, as well as malabsorption of nutrients that can decrease the health benefits of consumed foods. “Therefore, at the same time that energy requirement is decreasing, the need for many specific nutrients is increasing,” she said. “Vitamin B12, for example, is a common deficiency due to poor absorption as stomach acid decreases. This means that it is very important to choose nutrient-dense foods and to avoid empty calorie foods and, in cases of deficiency, supplements may be needed.”

Numerous observational studies looking at the effects of multivitamins on overall health as well as on specific health parameters have generated conflicting results. “The observational studies evaluating multivitamin use on various health outcomes have been mixed, but there are many methodologic limitations that have not been fully accounted for,” said Howard Sesso, ScD, MPH, an Associate Epidemiologist at the Divisions of Preventive Medicine and Aging at Brigham and Women’s Hospital, and an Associate Professor of Medicine at Harvard Medical School.

“For example, there are hundreds of multivitamin formulations on the market, making it difficult generalize multivitamin as a single category. We also know that those taking multivitamins may differ in important ways compared to non-users that observational studies try, but probably don’t optimally, account for,” he says.

The best evidence for any effects of a multivitamin on health comes from randomized clinical trials, for which only one long-term, large-scale trial—the Physicians’ Health Study II (PHS II), which included men aged 50 years and older—has been completed. A 2012 analysis of PHS II by Sesso and his colleagues found that multivitamins did not reduce major cardiovascular events, including myocardial infarction, stroke, and cardiovascular mortality, after more than a decade of treatment and follow-up.1

Daily multivitamin supplementation in PHS II has been found to modestly but significantly reduce the risk of total cancer.2 In addition, daily multivitamin use modestly and significantly decreased the risk of cataracts, but had no significant effect on visually significant age-related macular degeneration.3 Among male physicians aged 65 years or older in PHS II, long-term use of a daily multivitamin did not provide cognitive benefits.4

“We recently initiated a new clinical trial, the COcoa Supplement and Multivitamin Outcomes Study, or COSMOS, to examine the long-term health effects of multivitamin use in older women, plus see whether we can replicate in women the encouraging findings on cancer and cataract seen in PHS II,” said Sesso.

Although benefits of multivitamins may only be modest at best in healthy individuals, supplements containing combinations of certain nutrients can provide clear benefits for those who have, or are at high risk for, deficiencies.5 “In a patient with poor health status, nutrient status should be checked,” said Tucker. “Nutrient supplements make a big difference if there are deficiencies; however, too many supplements may also be harmful.” Tucker pointed to deficiencies in vitamins B12 and D as common among older patients, noting that these vitamins may need to be taken in doses higher than those contained in a standard multivitamin. On the other hand, care should be taken to avoid too much folic acid, iron, and preformed vitamin A, or retinol.

“The major multivitamin brands tend to represent safe products, so there is likely no downside to taking a multivitamin in addition to maintaining a healthy lifestyle and diet,” said Sesso. “But it remains unclear whether taking a multivitamin actually reduces disease risk, though PHS II did provide encouraging data that warrants replication.”

As a footnote, many health professionals look to reputable sites like these to ensure that supplement has been tested for purity and to ensure the amount listed on the label matches the amount in the supplement:

Multivitamins in Pregnancy ‘Are a Waste of Money’


Most moms-to-be who take multivitamin and mineral supplements are wasting their money because they are unlikely to need them, say researchers.

A review of available evidence, published in the Drug and Therapeutics Bulletin, says pregnant women who want to help ensure their baby has the best start in life should focus on improving their overall diet instead.

They should also follow official advice to take folic acid and vitamin D supplements, the researchers say.

Pregnancy Complications

Deficiencies in key nutrients have been linked to various complications during pregnancy and birth, including pre-eclampsia, restricted foetal growth, neural tube defects such as spina bifida, skeletal deformities and low birth weight.

This has led to a market in multivitamin and mineral supplements targeted specifically at pregnant women and marketed to protect their health and the health of their baby.

The review found these products typically contain 20 or more vitamins and minerals and cost around £15 per month.

Folic Acid and Vitamin D

The NHS recommends that pregnant women should eat a healthy, varied diet. Additionally, they should take:

10 micrograms of vitamin D each day throughout pregnancy and continue taking this supplement while breastfeeding

400 micrograms of folic acid each day before conceiving and until the 12th week of pregnancy to help prevent neural tube defects

5 milligrams of folic acid a day where there is a family history of neural tube defects or where they have diabetes or have had a previous baby with a neural tube defect

They are also caution against taking vitamin A supplements, or any multivitamin containing vitamin A (retinol), because too much could harm the baby.

Some women may be eligible for free vitamins through the Healthy Start scheme, which is designed to help poorer families in receipt of certain benefits.
The review found strong evidence to support the recommendation to take 400 micrograms of folic acid a day. Also, for women at a higher risk of having a child with neural tube defects, they agree with the advice that a 5 mg daily dose is appropriate.

The researchers say the evidence for taking vitamin D supplements is less clear-cut because little of the data available from trials showed any impact on reducing the risk of complications during pregnancy or at birth. However, they back the NHS advice for taking 10 micrograms each day to help ensure healthy bones and teeth.

Lack of Evidence

However, the researchers say nothing in the available evidence supports the use of multi-vitamin supplements for most mothers-to-be.

“We found no evidence to recommend that all pregnant women should take prenatal multi-nutrient supplements beyond the nationally advised folic acid and vitamin D supplements, generic versions of which can be purchased relatively inexpensively,” they say.

They point out that much of the evidence behind marketing claims for multivitamin supplements come from studies carried out in low income countries, where women are more likely to be undernourished or malnourished than women in the UK.

“For most women who are planning to become pregnant or who are pregnant, complex multivitamin and mineral preparations promoted for use during pregnancy are unlikely to be needed and are an unnecessary expense,” the review concludes.

However, the researchers recommend greater use of the Healthy Start scheme to ensure that low-cost tablets containing vitamin D, folic acid and vitamin C are made more widely accessible to women during pregnancy.

A Healthy, Varied Diet

Janet Fyle, from the Royal College of Midwives, comments in a statement: “We would encourage women who are pregnant or are thinking of becoming pregnant to have a healthy, varied diet including fresh fruit and vegetables, alongside taking folic acid supplements.

“We would also stress that there is no need for pregnant women to ‘eat for two’. This is a myth and all that is required is a normal, balanced amount of food.”

The industry-funded Health Supplements Information Service said the review “will only create confusion for pregnant women and dissuade more women from improving their vitamin and mineral intakes.”

Benifits vs Side Effects of Taking Multivitamins


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You aren’t getting enough nutrients needed and are thinking of increasing your vitamin intake, but where do you start? A multivitamin could solve your problem but first let’s take a look at the benefits vs side effects.

Everyone knows how important minerals and vitamins are for the body. The main reason people take multivitamins on a daily basis is that they believe that they are a safe alternative to staying healthy, but this isn’t true. Not everyone’s body needs a multivitamin unless they have some nutrient deficiency.

The Recommended Multivitamin vs. the Multivitamins with Additional Content

The perfect multivitamin contains around 100% of the recommended daily allowance of nutrients that are body needs to operate efficiently. However, if you have a deficiency like say an iron deficiency you may have to take a separate supplement along with the multivitamin.

There are also other types of multivitamins out there that are known as experimental multivitamins, but what’s the difference? Well unlike the regular these contain excess benefits such as phytonutrients and extra antioxidants. But this isn’t a good thing because if you aren’t careful they could cause you to develop cancer based on clinical studies, due to the high dosages. The increased risk of cancer in these products is attributed to the massive vitamin E content. Remember that you should exceed and take dosages above 400 IU; any more than that and you’re taking a gamble with your health.

It Pays to be a Smart Consumer

 Make sure when you take a trip to the market, you read labels and are always cautious when considering purchasing a multivitamin, because of the increased risk of developing cancer. So always research before you buy things you aren’t sure about.

Are Multivitamins a Necessity?

To be honest no. Multivitamins should always be taken with extreme caution and only when you have a good enough reason. And even though reading the label might be considered time-consuming, but do you want to put it in your body without knowing what’s in it?

Source:

http://www.encyclopedia.com/topic/vitamin.aspx

Is Taking a Multivitamin Worth the Risks?


Multivitamins are the most popular dietary supplement sold today. People of all demographics and age groups use multivitamins, and they’re often people’s first supplement. Since there are so many different multivitamin formulas, this supplement makes up an entire subsection of the supplement industry.

Vstock LLC/VStock/Getty Images

Multivitamins are often discussed in the media and online, though their use is rarely recommended against. Many articles and experts recommend a multivitamin as a general health supplement. However, multivitamins are made up of many different compounds, and it’s never a good idea to take a variety of supplements without a good and well-researched reason to do so.

Not everyone needs to supplement with a multivitamin. People with a nutrient deficiency that cannot be alleviated through dietary changes may experience benefits from supplementing with a multivitamin, but that also depends on the kind of multivitamin formulation they buy.

The standard multivitamin
The most commonly used and researched multivitamin formula contains 100 percent of the recommended daily intake (RDI) of nutrients the body needs. Some compounds, like magnesium and calcium, are physically too large to include in these capsules. Iron is also usually omitted.

Standard multivitamins are an effective and recommended supplement for people who do not get enough nutrients through their diet. Keep in mind, making dietary changes is both more effective and tastier than supplementing to alleviate a nutrition deficiency.

Though standard multivitamins are beneficial supplements for people living in low-income areas or food deserts without easy access to nutritional food, they are more often used as preventative supplements by people eating a varied diet. Though studies show there are no side effects from standard multivitamin supplements, they also don’t provide any benefits when taken by already-healthy people.

The experimental multivitamin

Some multivitamin formulas contain 100 percent of the RDI for essential vitamins, but also contain additional “antioxidant support” and other phytonutrients alongside questionable health claims.

These are the multivitamin formulas that tend to be associated with increased cancer risk in clinical studies, since most of the antioxidant claims are based on vitamin E content, which can be harmful at doses above 400 IU (18 times higher than the RDI).

Some additions are inert and have no effect, like increased vitamin C content, which has not been linked to any benefits. Other ingredients, such as lycopene, are included based on promising preliminary evidence, but likely have no effect when supplemented by people through a multivitamin.

These multivitamin formulas are marketed as an improvement over standard multivitamin formulas, but they are not recommended for supplementation. At worst, experimental multivitamins can be harmful to your health; at best, they’re a standard multivitamin with a higher price.

The surplus multivitamin
Even experimental multivitamin formulas tend to toe the line when it comes to the RDI of various nutrients. The third category of multivitamins, however, contains formulas that disregard serving sizes and established dosages.

Surplus multivitamins are marketed as general health supplements, whether they contain vitamin C, garlic or another herb. These multivitamins are not vitamins, they are combinations of other supplements and compounds.

Multivitamins and supplements that contain a variety of compounds but hide the doses behind proprietary blends should be avoided. There is no research done on these specific combinations. Existing research on individual supplements does not apply because supplements can act differently when taken together. When doses and ingredients are not available, it isn’t possible to determine the effects and health risks of the supplement.

Multivitamin supplements that list the amount of each ingredient can be supplemented safely, but should only be used if the included ingredients are effective supplements for your specific health goal.

Do I need a multivitamin?
Multivitamins, like all supplements, should never be used without a good reason. Before purchasing a new supplement, read the label and ask yourself:

1. What ingredients in this supplement are useful for my health goal?

2. What ingredients in this supplement are not useful for my health goal?

3. Will the ingredients hurt me or be counterproductive?

4. If I buy the ingredients individually, will it be more expensive than this supplement?

If the multivitamin isn’t harmful and isn’t more expensive than the sum of its parts, it may be worth considering for supplementation.

 

5 Vitamins You Might Be Overdoing.


Americans aren’t eating as many fruits and vegetables as we should be. In fact, Americans nationwide are significantly below the fruit and vegetable consumption guidelines set forth by the Centers for Disease Control and Prevention and the USDA.

Enter supplements. As people seek alternative sources of crucial vitamins and minerals, supplement intake has skyrocketed. Supplements can be helpful, but getting nutrients in a pill rather than food is not always the best way to improve your health. In some cases, it can even hurt.

vitamins you may be overdoing

Here are five vitamins and minerals you may be overdoing if you pop them as pills.

Iron and Copper

Iron plays a key role in younger women’s diets for menstrual cycles and pregnancy, but the recommendations for iron after menopause decrease significantly. Despite the lower guidelines (8 mg per day after age 50) many postmenopausal women still take supplements that contain iron. The risks of getting too much iron include a condition called hemochromatosis, which can damage your organs. Further, a 2010 study linked excess iron and copper to increased incidence of alzheimers disease and heart disease.

“Getting nutrients in a supplement rather than food is not always the best way to improve your health. Here are five vitamins and minerals you may be overdoing if you pop them as pills.”
Kristin Kirkpatrick, MS, RD, LD

Wellness Institute

Best bet: If you’re over 50, ditch the multivitamins with iron and copper unless a doctor instructs you to take them.

Beta-carotene

Beta-carotene and vitamin A — which is formed by beta-carotene — is easy to consume. If you have a bowl of cereal for breakfast, anything orange (carrots, sweet potatoes) for lunch and then a multivitamin or supplement for eye health, you’ve probably consumed too much. Too much beta-carotene has been associated with increased risk for lung cancer and overall increased risk of death.

Best bet: Skip the supplement and stick to food sources such as sweet potatoes, watermelon, cantaloupe, red bell peppers, carrots and spinach.

Vitamin C

When most people think of vitamin C, they think of oranges. But if your first thought is a vitamin C pill, you may be overdoing it. A recent study found that men who took vitamin C pills had higher risk for developing kidney stones.

Best bet: Enjoy the culinary delights of vitamin-C rich foods such as papaya, strawberries, brussels sprouts and kale. But don’t take extra unless a doctor advises you to.

Calcium

While calcium is important for strong bones, data suggests getting too much of it can strain your heart. Studies have suggested that women who take high amounts of calcium increase their risk of cardiac death and moderately increase their risk for heart attack.

Best bet: To avoid overdoing it, get your calcium through food sources such as dairy, tofu, sardines, broccoli and almonds. If you think you need supplemental calcium, talk to a doctor before buying a bottle.

The recommended daily allowance for any vitamin or mineral will depend on your age, medical conditions and other factors, and a doctor or registered dietitian can help you fine-tune your intake.

You may also notice a common theme here: Most vitamins and minerals are best obtained and absorbed through real food. To ensure you’re getting enough — but not too much — of any vitamin or mineral, avoid supplements that contain “mega doses” unless your doctor recommends them for medical reasons.

 

No Benefit of Multivitamins for Preventing Cardiovascular Disease in Men.


A randomized, controlled trial showed that myocardial infarction, stroke, and death were not affected.

Observational studies of multivitamins for preventing cardiovascular disease (CVD) have yielded inconsistent and mostly negative results, as have randomized controlled trials of individual vitamins and minerals (including β-carotene, selenium, and vitamins B, C, and E). This randomized controlled trial that involved nearly 15,000 male physicians (mean age, 64) who were randomized to commercial daily multivitamins (Centrum Silver) or placebo is a companion analysis to a recently published study that showed a small benefit of multivitamin supplementation for preventing cancer (JW Gen Med Oct 25 2012). Follow-up continued for a median of 11 years.

No difference was found between the groups in risk for any major adverse CVD event, including myocardial infarction, stroke, or cardiac-related mortality. Multivitamin supplementation also was not beneficial in the small subgroup of men with histories of CVD at study entry (5% of participants).

Comment: These findings appear to disprove the suggestion (or hope) that vitamin supplementation prevents CVD, at least in men. The cardiovascular and cancer outcomes from this trial will help clinicians answer patients’ questions about the value of multivitamins; additional results from this study (i.e., on preventing eye disease and cognitive decline) are forthcoming.

Source: Journal Watch General Medicine

 

 

 

 

Do multivitamins inoculate you against cancer?


You can’t blame somebody for wanting a silver bullet to protect them from cancer. And this desire may partly help explain why Americans spend upwards of $20 billion a year on vitamins and supplements.

After all, we know that eating a diet heavy in fruits and vegetables plays a big role in reducing cancer risk. And it seems reasonable to assume that vitamins in these foods are the ingredients behind this preventative effect, and that consuming them via pills or supplements will protect against the disease. The problem is, researchers can’t confirm that vitamins—or any other particular ingredients—account for the reduced risk.

“There must be something in the foods that’s doing this, but it’s been hard to isolate exactly what it is,” says the Hutchinson Center’s Dr. Emily White. “It might be a vitamin, or a mineral, or a range of nutrients from different foods that work together in a way you can’t replicate in a pill.”

Dr. Emily White

Continued research may shed more light on role of vitamins and other supplements

White has spent several years tracking how 38 different supplements impact the health of more than 75,000 study participants. Her goal is to see if people who take certain supplements are diagnosed with cancer more or less frequently than people who don’t take them.

So far, some of the strongest findings have centered on multivitamins. The bottom line?  “In general, there’s no strong evidence that taking a multivitamin increases or decreases your cancer risk,” White says.

Another Hutchinson Center study reached a similar, if more gender-focused, conclusion. Led by Dr. Marian Neuhouser and published in 2009, the study looked at multivitamin use among 161,000 women and found that taking multivitamins did not affect the likelihood of contracting cancer or cardiovascular disease.

Dr. Marian Neuhouser

But what about more specific vitamins? After all, the world is awash in claims that particular supplements, ranging from vitamin D to fish oil, can prevent particular cancers. While White says there’s a lot of work left to be done in this area, she pointed to a number of studies that have started testing some of the most common claims:

  • After preliminary research suggested that vitamin E and selenium could help prevent prostate cancer, Hutchinson Center researchers contributed to a 2008 study, published in the Journal of the American Medical Association, finding that these supplements had no impact on prostate cancer risk.
  • Carrots and their component beta carotene have also been said to decrease prostate cancer risk. But, after conducting clinical trials of beta carotene and retinyl palmate, a research team that included Neuhouser and the Hutchinson Center’s Dr. Alan Kristal and Matt Barnett found that these supplements do not prevent prostate cancer. In fact, the evidence suggests that taking these supplements in high doses may increase the risk of contracting the disease.
    Dr. Alan Kristal

  • Vitamin D supplements are often pegged as a way to stave off colorectal cancer. However, our Dr. Andrea LaCroix led a study of 36,000 postmenopausal women showing that calcium and vitamin D supplements did not impact incidence of the disease.

Research focuses on fish oil

Of course, this is only the beginning. With hundreds of supplements on the market, there may be some that have anti-cancer effects. Researchers here and elsewhere are doing their best to identify these; a Harvard University team, for instance, recently launched a randomized trial studying the health effects of fish oil, a supplement of interest to White.

Last year, she published a study that found high levels of the omega-3 fatty acids EPA and DHA were associated with a 32 percent reduction in breast cancer risk. However, she cautioned against gleaning any recommendations from the results of one study.

Until scientists can establish a clearer link between supplements and cancer, White has some simple advice for consumers tempted by the pills and powders beckoning from the health food aisle. “You should be shopping in the produce section instead,” she says.

source:  Fred Hutchinson Cancer Research Center