December 10, 2010 – The American Institute of Medicine (IOM) and Health Canada have tripled the recommended dietary allowance (RDA) of vitamin D: it went from 200 IU to 600 IU for the population aged 1 to 70 years. For those 70 and over, the intake has been set at 800 IU.
The revision of the RDA for vitamin D was eagerly awaited by many researchers who wanted a substantial increase, but many were disappointed with the conservatism of the IOM.
The IOM report
In the case of calcium and vitamin D, the first standardized recommendations between the American and Canadian governments were established in 1997. Faced with the debate that has since raged about the preventive effect of vitamin D against several diseases, a committee experts – the IOM – was therefore mandated to scrutinize the new scientific data. Here are his conclusions1.
- The IOM has found strong and compelling new data on the benefits of vitamin D for bone health. Based on this, the experts were able to set a recommended nutritional intake of vitamin D, rather than a sufficient intake.2, as was the case before. See the tables below.
- The in-depth review of the IOM, however, revealed often conflicting or inconclusive results regarding the protective effect of vitamin D against cancer, cardiovascular disorders and diabetes, on immunity, etc. The committee therefore did not take these data into account to make a public health recommendation.
- According to surveys carried out in both countries, the majority of Canadians and Americans have a blood level of vitamin D sufficient to ensure good bone health, or 50 nanomoles per liter (nmol / l). Health Canada and the IOM therefore conclude that the majority of the population does not have to modify their dietary intake of vitamin D and do not need to take supplements.3.
- In addition to setting RDAs, the IOM establishes, for certain vitamins and minerals, a maximum tolerable intake (AMT). Vitamin D AMT increased from 2,000 IU to 4,000 IU per day because, according to the committee, preliminary trials suggest that undesirable effects are possible beyond this dose.
The reactions
Reinhold vieth
“I’m glad the vitamin D intake has been increased, but it’s nowhere near enough,” says Reinhold Vieth, professor in the Department of Nutritional Sciences at the University of Toronto. An RDA of 600 IU is just enough for good bone health, but it is not enough to reap the other benefits of vitamin D. ”
According to him, the data concerning the prevention of diabetes, colon cancer and breast cancer are the most promising. “But all this work was rejected out of hand, because the level of proof required to set a recommended intake is the same as for the marketing of a drug,” he protested.
His opinion is shared by John H. White, professor in the Departments of Physiology and Medicine at McGill University. “We now have substantial and convincing evidence that vitamin D, in addition to its usefulness for bone health, reduces the risk of several cancers, contributes to cardiovascular health and stimulates the immune response in infectious disease,” he said. member of the scientific panel of Vitamin D * action4, on the website of this group5.
Professor Vieth, like several other members of Vitamin D * action, strongly disagrees with the blood level of vitamin D considered adequate by the IOM. “If a level of 50 nmol / L is sufficient, why do ethics committees require 75 nmol / L for participants in a study on the treatment of osteoporosis?” This contradiction makes no sense! He exclaims.
Foods or supplements?
In a press conference, the chair of the IOM committee clarified that for most Canadians and Americans, the diet is sufficient to reach the recommended intakes of vitamin D. “This is wrong! », Answers Reynold Vieth. “Here again, the authorities contradict each other. For example, Canada’s Food Guide, which dates from 2007 and is based on an intake of 400 IU per day, recommends that adults over 50 take a supplement of 400 IU of vitamin D. no logic to say that we can get 600 IU per day in our food. ”
A view shared by Edward Giovannucci, professor of nutrition and epidemiology in the School of Public Health at Harvard University. “Although there is no clear proof, taking 1,000 to 2,000 IU of vitamin D in supplement form every day seems justified to me,” he says in the Vitamin D * action site.5.
Even if the maximum tolerable intake has been doubled, Professor Vieth questions it. “It’s double standards,” he says. We need concrete proof to say that vitamin D can help prevent diabetes, but to say that it can be dangerous from 4000 IU, we are satisfied with very poorly supported data. It is known that the body can make up to 10,000 IU when exposed to the sun. It would be logical to consider that what the body manufactures itself is safe. “
That said, he recognizes that vitamin D, like any molecule that affects human health, can cause unwanted effects if taken in excess.
Recommendations
The Canadian Cancer Society maintains its recommendation, established in 2007, to take 1,000 IU of vitamin D per day as a supplement in the fall and winter: “Our message remains the same. Part of cancer prevention strategies is taking 1,000 IU of vitamin D per day as a supplement. Although current studies do not allow a definitive conclusion, the benefit / safety ratio of vitamin D is very good, ”says spokesperson André Beaulieu.
For his part, pharmacist Jean-Yves Dionne, an expert in natural health products, considers the new intakes much too low and says in his blog6 that he will continue to take “4,000 IU per day of vitamin D (at least 8 months per year) until proven otherwise”.
Recommended intake of vitamin D since December 2010
|
age |
Amount |
AMT |
|
From 0 to 12 months |
400 IU |
2000 IU |
|
from 1 year to 70 years |
600 IU |
4000 IU |
|
over 70 years |
800 IU |
4000 IU |
Adequate intake * of vitamin D before December 2010
|
age |
Amount |
AMT ** |
|
from 0 to 50 years old |
200 IU |
1000 IU |
|
from 51 to 70 years old |
400 IU |
2000 IU |
|
over 70 years |
600 IU |
2000 IU |
* In the absence of sufficient scientific data, the IOM had set, in 1997, not a recommended nutritional intake (RDA), but a sufficient intake (AS). Adequate Intake is a Recommended Average Daily Intake based on the Average Intakes in healthy North Americans.
** Maximum tolerable intake (AMT). Maximum amount of a nutrient that the majority of the population can ingest continuously without risking adverse health effects.
|
Respond to this news in our blog Vitamin D, the health star of the year 2010! |
Françoise Ruby- PasseportSanté.net
1. Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Report Brief – November 2010. www.iom.edu [Consulté le 30 novembre 2010]
2. IOM press conference regarding recommended intakes of vitamin D and calcium, held on November 30, 2010. www.visualwebcaster.com
2. In the absence of sufficient scientific data, the IOM sets, not a Recommended Dietary Allowance (RDA), but an Adequate Intake (AI). AI is a Recommended Average Daily Intake based on the average intakes in healthy North Americans.
3. Health Canada. Food and Nutrition. Vitamin D and Calcium: Revision of the Dietary Reference Intakes. www.hc-sc.gc.ca. [Consulté le 1er décembre 2010]
4. Vitamin D * action is a group of 41 scientists and institutions who recommend having their vitamin D level measured in order to detect a possible vitamin D deficiency, a situation that they believe would be generalized in Canada and the United States. .
5. Vitamin D * action. Quotes on the State of Vitamin D Science, Reference to IOM Report from the D * action Panel of Vitamin D Scientists / Researchers. www.grassrootshealth.net [Consulté le 9 décembre 2010]
6. Dionne, Jean-Yves, An old vitamin that makes headlines [Consulté le 1er décembre 2010]
