Expert advises against high doses of supplements

(Medical Xpress) -- That vitamin D and calcium you're taking could be causing more harm than good, a new article in the Journal of the National Cancer Institute says.

The paper, co-authored by a professor at the University of Arizona's Mel and Enid Zuckerman College of Public Health, cites evidence that high doses of some supplements increase .

"You may not need to take supplements if you have a ," said article co-author Elizabeth Jacobs, a UA associate professor of epidemiology and a researcher at the Arizona Cancer Center. She cited an old phrase: "The dose makes the poison."

"If you are deficient in nutrients, taking a supplement is probably not going to cause any harm, but if you are already adequate in nutrients, then taking a supplement at a minimum has no benefit and in some cases has been shown to cause harm," Jacobs said.

Jacobs said the authors are not trying to say people who take supplements will get cancer. But she cautions about taking megadoses like 10,000 I.U.s of vitamin D per day, for example.

"A lot of literature has shown that often the people who take dietary supplements need them the least, so they already eat a good diet, they have a lot of nutrients in their diet, they exercise, they don't necessarily need extra nutrients," Jacobs said. "And those are the people who tend to take supplements - they are very health conscious, and that's where the danger is because you are already getting enough of these vitamins or minerals in your diet, and then you are adding more."

The article, titled "Dietary Supplements and : Balancing Potential Benefits Against Proven Harms," appeared in the April 25 issue of the Journal of the . Its lead author is María Elena Martinez of the University of California-San Diego, who is a former UA College of Public Health epidemiology professor.

"Undoubtedly, use is driven by a common belief that supplements can improve health and protect against disease, and that at worst, they are harmless," the scientists write. "However, the assumption that any dietary supplement is safe under all circumstances and in all quantities is no longer empirically reasonable."

In an email, Martinez stressed that the article is not a study but rather an invited commentary that she hopes will "continue to increase awareness among the scientific community, policymakers and relevant government agencies about the scientific evidence on the topic, especially as it relates to harm related to these products."

Nutritional supplements are an estimated $30 billion-per-year industry.

"If you have too much of anything, that is not a good thing," said Cara Welch, vice president of scientific and regulatory affairs for the Washington, D.C.-based Natural Products Association, a nonprofit group representing natural-products retailers and suppliers. "The article was looking at very high doses in particular populations. It is against the law to market your supplement to treat or prevent cancer - at that point it turns into a drug. There's no way around it. You can't imply you prevent cancer."

Both Martinez and Jacobs say there are certainly people who need supplements, such as women of childbearing age who are considering getting pregnant, people who have been diagnosed with a specific nutrient deficiency like anemia and people with food allergies or intolerances, like lactose intolerance.

Folic acid is recommended for women considering pregnancy, but it is an example of a supplement that could be harmful for people who don't need it, Jacobs said.

"When you are older, folic acid is shaking out to be one of the more worrisome supplements," Jacobs said. "It's not natural. It's completely synthetic folic acid, and so your body is getting this new compound and we're just not as efficient at metabolizing folic acid as folate. So that is some cause for concern."

Jacobs said her personal hope is that the article will inspire better regulation and oversight of the supplement industry.

For most claims made in the labeling of , the law does not require the manufacturer or seller to prove to the government's "satisfaction" that the claim is accurate or truthful before it appears on the product, Food and Drug Administration literature says.

Welch said her organization has a research and education arm that works with companies to ensure "truth in advertising."

And the industry is not regulated in the same way as pharmaceuticals for a reason, she said.

"We're not regulated as drugs because we're not drugs," she said.

Welch said a majority of Americans take supplements like multivitamins and Omega-3 to maintain health. "Unfortunately, the standard U.S. diet doesn't give us all the nutrients we need," she said.

None of the article's five scientist authors takes any , not even the much-heralded , Jacobs said.

"Eat a variety of food, exercise, don't smoke - that is superior to taking a supplement," Jacobs said. "You aren't supposed to get the recommended dietary allowance (of nutrients) every day. It rarely happens. You are supposed to just average over time. You just do the best you can. But in the U.S. our problem isn't really under-nutrition, it's over-nutrition."

"You aren't supposed to get the recommended dietary allowance (of ) every day. It rarely happens. You are supposed to just average over time. You just do the best you can. But in the U.S., our problem isn't really under-nutrition, it's over-nutrition."

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May 04, 2012
The real guide-point for supplementation is level of activity. If you are a postal worker and you are on a rural route that you walk and you are also a bodybuilder...there is a very good chance that you CANNOT eat enough to recover nutritionally, from both activities, without eating a ton of food per day. Differing rates of growth at various stages of life combined with a pregnancy or recovering from catastrophic health challenge, supplementation can save your life. Sitting at a computer all day, then riding the bus home in Shanghai, Berlin, New York, LA, etc...your exposure to contaminants, pollutants, and prolonged sitting means Resveratrol and vitamin C and a broad range of super-foods now available on the open market need to be in your briefcase/purse along with a standard multivitamin. The article makes a valid point, oh yeah, yes. But, each person has got to get to know themselves, their family history, and then choose wisely as only they can.

Live long and Prosper...

May 05, 2012
I have not read the article yet. Let me guess what he/she will say. They will point to the cheapest to make least helpful form of vitamin E and a precursor to vitamin A beta carotene.

May 05, 2012
This person makes money off of drugs and pharma kickbacks. The purpose of the regular and continued attack on nutrition is to reclassify it as a drug and be able to charge enormous prices for it abusing capitalism. Furthermore these big pharma backing doctors attacking nutrition are not doing their jobs because the obesity, overweight and diabetes rates keeps climbing while pharma plays ads to us for drugs we are not allowed to prescribe to ourselves.
They will take this to an extreme and abuse capitalism if you let them. They are approaching reclassifying water as a drug because it cures dehydration. Their has to be a line drawn in the sand that they cannot cross. Most of their drugs come from copying nature and modifying it and then they turn around and go, "wait, no, that flavanoid you can't say it helps your health but I can because I just copied it and changed it a little bit and sell it for enormous cost."

May 05, 2012
Not only is this biased and written by people who make money off of, "drugs are solutions not nature pay me pay me pay me pay me" it is totally ignorant. INGNORANT. Ignorant of the synergy and long term affects of taking vitamins WITH co-factors, bioflavonoids, other nutritionals and hormone balancing. And it makes me very mad when doctors put out this misleading crap.
1) Why are your big pharma putting ads on tv for us for drugs only doctors can prescribe?
2) Since the FDA came into existence US health has got worse.
3) Look at where the execs of FDA come from and where the FDA have their stocks
4) You are not doing your job. The problem is not over nutrition and you know it. It is sugar and all the other crap you let them put in our food because the food industry is in bed with the FDA. And Monsanto, you let them GMO contaminate regular farmers crops and then sue the farmer for GMO theft. WHERE ARE YOU DOCTORS!? standing up for healthy food?

May 05, 2012
Theanine: This is an >>amino acid<< one of the building blocks of life, you know like when your stomach breaks down a protein and it becomes amino acids that your body absorbs. Except this one only exists in certain plants and it's not part of a protein. It is sold as a supplement and crosses the blood brain barrier. It is a nutritional because you consume it from the leaves of plants when you make tea. IT HELPS YOU AND HAS HEALTH BENEFITS too bad if you don't like it that it's not a drug and you can't charge $100 a pill for it and get kick backs from big pharama you sleaze bag capitalism abusing dirtbag "doctors" of america.

Is it in our food, our bread, our tortillas, our cheese, cream cheese, milk, sauces, etc, etc,? NO! But what is in our food? A BUNCH OF CRAP preservatives and dyes and corn syrup and others that you APPROVE of with your support of the FDA and not speaking out and denial of the big pharma corruption
Ubiquinol (Jap)
Acetyl L Carnitine Arginate
lots more

May 05, 2012
New vitamin discovery
Yeah it's a new vitamin
PQQ - Pyrroloquinoline quinone

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