A report, “Dietary Reference Intakes for Calcium and Vitamin D,” was issued by the National Academy of Sciences Institute of Medicine, on November 30th. This was reported by the press in a way that created a great deal of confusion and concern. Most of this concern was misguided, and unnecessary.
There are several things to bear in mind, right off the bat. First, the headlines in some of the newspapers and news broadcasts do not accurately reflect what was actually contained in the study. You can easily see that this is the case by merely comparing the headlines from The New York Times with that of The Wall Street Journal on the morning of November 30th. “Extra Vitamin D and Calcium Aren’t Needed” was the headline in the Times, while “Triple That Vitamin D Intake, Panel Prescribes” was the headline in The Wall Street Journal.
Could they have been talking about the same study? Yes, they were. Hard to believe, isn’t it? This is an excellent example of letting your agenda dictate your reaction.
So which is it? Does the study say you don’t need vitamin D and calcium, or your need more? The answer is yes. You have to bear another thing in mind, and that is the identity of the authors–The Institute of Medicine. Wonderful folks, I’m sure, but these are the people responsible for determining those levels of vitamins and minerals necessary to prevent deficiency diseases–scurvy, pellagra, beri-beri, rickets, etc. They create the data (DRI’s, etc) historically utilized in setting the MDR’s, the RDA’s, and the DV’s.
There is nothing wrong with this, of course. But that is not what most of us taking supplements are concerned about. We are not looking to take just enough supplemental vitamins to prevent overt deficiencies. Instead, we are taking supplements in an attempt to achieve optimal health, to prevent various other types of disease, aging and deterioration, and, in some cases, we take supplements for their therapeutic value.
If you do not bear this distinction in mind, you risk missing the point of the study. Saying that we need to increase the amount of vitamin D by three-fold, but do not need more–which is what the study recommends–can be interpreted differently, as it suits you purpose.
Everyone agrees that vitamin D is essential to maintaining strong bones. But hundreds of studies in recent years have linked low vitamin D levels to a higher risk of chronic health problem such as heart disease, stroke, diabetes, prostate cancer, breast cancer, colon cancers, auto-immune diseases, infections, depression and cognitive decline. At the same time, concern about levels of vitamin D have increased because of the increased use of sun screen and reduced exposure to sunlight.
The Institute of Medicine based its new recommendations on the levels needed to maintain strong bones. They said there wasn’t enough evidence to prove that low vitamin D causes such chronic diseases. The key word here is “prove.”
“The evidence for bone health is compelling, consistent and gives strong evidence of cause and effect,” said Patsy Brannon, a professor of nutritional sciences at Cornell University and member of the IOM panel. For the other health problems, she said, “there are relatively few randomized controlled trials, and even in the observational studies, the effects are inconsistent.”
When is “proof” necessary? Do I need “proof” to conclude that jumping out of an airplane without a parachute is not good for my health? If there are hundreds of studies that indicate that high levels of vitamin D may prevent or treat heart disease, enhance immune function, prevent various cancers, depression, and diabetes, and no evidence that these levels are harmful, and at little cost to me, just how much more “proof” do I, or any reasonable person need?
Maybe not all of those studies are “randomized, controlled trials.” Maybe the effects are “inconsistent.” But maybe, in a case like this, that is good enough. It may not be good enough for the Institute of Medicine, but it is good enough for you and me.
Good enough, because that may be the best we can get. Be wary of those who imply that all medical studies, such as those supporting the approval and use of conventional pharmaceutical drugs are ironclad “proof.” We know that is not the case. The type of studies that would provide the proof we are looking for are difficult to design, and expensive to run. There is little incentive for anyone to do so.
Even those who worship at the alter of “proof” often do so only when it suites their purpose. This, it seems, is the case for the Institute of Medicine as well. If you read the article in The New York Times carefully, you will see the hypocrisy:
“After reviewing the data, the committee concluded that the evidence for the benefits of high levels of vitamin D was ‘inconsistent and/or conflicting and did not demonstrate causality.’” So all of these studies are dismissed. Yet they go on to say “Evidence also suggests that high levels of vitamin D can increase the risks for fractures and the overall death rate and can raise the risk for other diseases. While those studies are not conclusive, any risk looms large when there is no demonstrable benefit. Those hints of risk are ‘challenging the concept that ‘more is better,” the committee wrote.”
So “inconclusive and inconsistent studies” are dismissed when they do not agree with your position, but similar studies are accepted when they do support your agenda?
This comment at the end of the report in the Wall Street Journal sums it up nicely: “I supplement patients who are deficient and they feel better. They come in and say, ‘I’ve been much less achy and stiff or my mood’s been better since I’ve been taking the vitamin D,’ said Alan Pocinki, an internist in Washington D.C. Most of his patients are office workers, and 75% of them are below the 30 ng/ml level he considers necessary. ”
“Do we have the data to prove this conclusively? No. We don’t have evidence for much of what we do in medicine, but if you wait for the evidence, you may be depriving your patients of beneficial treatments,” Dr. Pocinki said.
December 4, 2010