Navigation Links
Increase in RDA for vitamin C could help reduce heart disease, stroke, cancer
Date:7/16/2012

CORVALLIS, Ore. The recommended dietary allowance, or RDA, of vitamin C is less than half what it should be, scientists argue in a recent report, because medical experts insist on evaluating this natural, but critical nutrient in the same way they do pharmaceutical drugs and reach faulty conclusions as a result.

The researchers, in Critical Reviews in Food Science and Nutrition, say there's compelling evidence that the RDA of vitamin C should be raised to 200 milligrams per day for adults, up from its current levels in the United States of 75 milligrams for women and 90 for men.

Rather than just prevent the vitamin C deficiency disease of scurvy, they say, it's appropriate to seek optimum levels that will saturate cells and tissues, pose no risk, and may have significant effects on public health at almost no expense about a penny a day if taken as a dietary supplement.

"It's time to bring some common sense to this issue, look at the totality of the scientific evidence, and go beyond some clinical trials that are inherently flawed," said Balz Frei, professor and director of the Linus Pauling Institute at Oregon State University, and one of the world's leading experts on the role of vitamin C in optimum health.

"Significant numbers of people in the U.S. and around the world are deficient in vitamin C, and there's growing evidence that more of this vitamin could help prevent chronic disease," Frei said. "The way clinical researchers study micronutrients right now, with the same type of so-called 'phase three randomized placebo-controlled trials' used to test pharmaceutical drugs, almost ensures they will find no beneficial effect. We need to get past that."

Unlike testing the safety or function of a prescription drug, the researchers said, such trials are ill suited to demonstrate the disease prevention capabilities of substances that are already present in the human body and required for normal metabolism. Some benefits of micronutrients in lowering chronic disease risk also show up only after many years or even decades of optimal consumption of vitamin C a factor often not captured in shorter-term clinical studies.

A wider body of metabolic, pharmacokinetic, laboratory and demographic studies suggests just the opposite, that higher levels of vitamin C could help reduce the chronic diseases that today kill most people in the developed world heart disease, stroke, cancer, and the underlying issues that lead to them, such as high blood pressure, chronic inflammation, poor immune response and atherosclerosis.

"We believe solid research shows the RDA should be increased," Frei said. "And the benefit-to-risk ratio is very high. A 200 milligram intake of vitamin C on a daily basis poses absolutely no risk, but there is strong evidence it would provide multiple, substantial health benefits."

An excellent diet with the recommended five to nine daily servings of fruits and raw or steam-cooked vegetables, together with a six-ounce glass of orange juice, could provide 200 milligrams of vitamin C a day. But most Americans and people around the world do not have an excellent diet.

Even at the current low RDAs, various studies in the U.S. and Canada have found that about a quarter to a third of people are marginally deficient in vitamin C, and up to 20 percent in some populations are severely deficient including college students, who often have less-than-perfect diets. Smokers and older adults are also at significant risk.

Even marginal deficiency can lead to malaise, fatigue, and lethargy, researchers note. Healthier levels of vitamin C can enhance immune function, reduce inflammatory conditions such as atherosclerosis, and significantly lower blood pressure.

  • A recent analysis of 29 human studies concluded that daily supplements of 500 milligrams of vitamin C significantly reduced blood pressure, both systolic and diastolic. High blood pressure is a major risk factor for heart disease and stroke, and directly attributes to an estimated 400,000 deaths annually in the U.S.

  • A study in Europe of almost 20,000 men and women found that mortality from cardiovascular disease was 60 percent lower when comparing the blood plasma concentration of vitamin C in the highest 20 percent of people to the lowest 20 percent.

  • Another research effort found that men with the lowest serum vitamin C levels had a 62 percent higher risk of cancer-related death after a 12-16 year period, compared to those with the highest vitamin C levels.

Laboratory studies with animals which may be more accurate than human studies because they can be done in controlled conditions and with animals of identical genetic makeup - can document reasons that could explain all of these findings, Frei said.

Critics have suggested that some of these differences are simply due to better overall diet, not vitamin C levels, but the scientists noted in this report that some health benefits correlate even more strongly to vitamin C plasma levels than fruit and vegetable consumption.

Scientists in France and Denmark collaborated on this report. Research at OSU on these issues has been supported by the National Center for Complementary and Alternative Medicine, a division of the National Institutes of Health.


'/>"/>

Contact: Balz Frei
balz.frei@oregonstate.edu
541-737-5078
Oregon State University
Source:Eurekalert

Related medicine news :

1. BASPCAN - UK-wide increase in number of children
2. MP3 song-searching can increase risk for drivers
3. Saliva test could dramatically increase detection of oral cancer
4. Regular jogging shows dramatic increase in life expectancy
5. Email vacations decrease stress, increase concentration, researchers say
6. Comorbidities increase risk of mortality in COPD patients
7. Could Eating Fast Increase Diabetes Risk?
8. For Dementia Patients, Feeding Tubes May Increase Bed Sores
9. Reported increase in older adult fall deaths due to improved coding
10. Chemotherapys effect on overall survival seems to increase based on tumor size
11. Dietary supplements increase cancer risk
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/23/2017)... ... ... METTLER TOLEDO has announced the availability of a new ... . , Crystallization is a common step used during the synthesis ... spend more time developing better intermediate and final crystallization steps. By adopting ...
(Date:1/23/2017)... ... January 23, 2017 , ... ... American Society of Anesthesiologists® (ASA®), the Foundation for Anesthesia Education and Research ... Surgeons (AAOS) and the Cigna Foundation, encourages proposals supporting high quality research ...
(Date:1/23/2017)... ... ... Under Blankets”: an entrancing story about one woman's travels through the wilderness of ... published author, Kimberly Mitchell, who earned her bachelor’s degree in English education at the ... degree in education in the field of curriculum and instruction. Kimberly’s passion for writing ...
(Date:1/22/2017)... California (PRWEB) , ... January 22, 2017 , ... "Photo ... Cloud to create a beautiful 3D slideshow with complete ease," said Christina Austin - ... Generators browser to place in the FCPX timeline. Presets include scenes with ...
(Date:1/21/2017)... ... January 21, 2017 , ... Seamild, the largest manufacturer of oats in China, ... owner and founder. As Oat is recognized globally as one of the healthiest cereals, ... he believes it is a move to sow the seed of good karma. Buddhism ...
Breaking Medicine News(10 mins):
(Date:1/23/2017)... 23, 2017 7D Surgical announced today ... the U.S. Food and Drug Administration (FDA) and ... the North American commercial launch of its innovative ... surgery, the 7D Surgical System.  ... technologies and machine vision algorithms to eliminate the ...
(Date:1/23/2017)... Jan. 23, 2017 The American Pharmacists Association ... Pharmacy and Medically Underserved Areas Enhancement Act ... The legislation, which was previously introduced in the 114 ... to health care through pharmacists and their patient care ... Brett Guthrie (R-KY), G.K. Butterfield ...
(Date:1/23/2017)... , January 23, 2017 Stock-Callers.com today ... Inc. (NASDAQ: CPRX ), Sophiris Bio Inc. (NASDAQ: ... MNTA ), and Agile Therapeutics Inc. (NASDAQ: AGRX ... turned somewhat lower in late trade on Friday, January 20 ... about 0.3%, while shares of health care companies in the ...
Breaking Medicine Technology: