The medical community is reacting this week to news that most Americans are not as deficient in vitamin D as was previously thought.
The Institute of Medicine panel just revised the recommendations for taking vitamin D supplements and calcium. The panel now recommends lower daily doses of both supplements.
MPR News medical analyst Dr. Jon Hallberg joined All Things Considered's Tom Crann on Thursday to discuss how the news is playing out in the clinic.
Hallberg is a physician in family medicine at the University of Minnesota and medical director of the Mill City Clinic in Minneapolis.
Tom Crann: What was your reaction right away when you read about this?
Dr. Jon Hallberg: My heart is sinking because these recommendations are really flying in the face (of) everything that I've been hearing a lot of lately. I mean just in the last two weeks I've written probably half a dozen prescriptions for high dose vitamin D, replacing levels (for) people who have low amounts in their bodies.
Crann: So why did they adjust them then?
Hallberg: This is really interesting. I don't know the whole back story behind this, but there's no doubt that there's been some pushback at ... a high level with all of the conversation and all of the activity that's been going on about vitamin D.
I mean I think it's to an extreme. People have (thought) that it's just like this panacea - that if everyone took more vitamin D, we would reduce diabetes, pain, suffering, heart disease, cancer. I mean the list is really almost too good to be true. So this is a pushback to that. And this is the Institute of Medicine.
This is an august national body. It was tasked by the U.S. and Canadian governments to come up with these new guidelines to ... sort through this. They sorted through a thousand studies. So this is not a light undertaking. This is a really major, major report that came out.
Crann: And they basically cut the recommendation in half or even less? It was what, 1,000 to 2,000 units, now it's down to 600?
Hallberg: Right, well for years and years, the daily recommended amount was about 400, maybe 800 international units a day, but what's been happening in common practice is that people have been encouraged to take 1,000 to 2,000 international units of vitamin D per day. They came up with 600 as ... the new adequate amount.
Crann: So vitamin D and calcium, they get linked here in this study, and when it comes to bone health, too. What's the connection there?
Hallberg: You need adequate amounts of vitamin D to absorb calcium out of the gut and to put it into the bloodstream so that it can be delivered to the bones for good bone health. If you don't have enough vitamin D, and really a low, low amount, and especially as you're developing as a child, you can develop rickets. And this is a condition that still exists in the world. We see it here in the United States a little bit, but not the way that we once did.
Crann: So vitamin D comes from sunshine. What about those of us in northern climes. We're beginning the winter here. Do we need to be more concerned about this?
Hallberg: So the thought has been that if you live above a certain latitude in the United States, you need extra vitamin D because there's simply no way with the angle of the sun and the fact that we're bundled up in the winter, that you're getting enough. I think this is still going to be a big, big point of contention - that people are going to argue that we truly do not, that you can't store adequate amounts through the entire year, (that) you need something in the form of a supplement. So this is going to be played out, I think.
Crann: How do people know if they're getting enough vitamin D, whether it's through food supplements or sunshine?
Hallberg: Well we can do a vitamin D test, and this is being done a lot. I think what's happened - and this is another thing in the report that came out - is that many people are getting it as a routine test, like a cholesterol level, for example, when they come in for an annual physical exam. And I think many of us reserve that test when we think it's appropriate - people have chronic pain, they're incredibly fatigued, we've worked up other avenues and we've not found a source of their symptoms, then we'll add it. And the report is certainly encouraging us not to be checking this on a regular basis. At least that's my sense.
Crann: So Jon, what's your advice for most patients who come in? Should anyone actually be taking a vitamin D supplement or calcium supplement?
Hallberg: That's the big question. I think that what's coming out of this report, and it really kind of captures a big question, and that is: Should any of us be taking anything without some very important deep thought about it? I mean I really think this is getting at that.
I think that large doses of vitamin D - without knowing a level, without having a conversation about this - is probably unnecessary. At least that's the consensus from this report. I know that there are many, many physicians and many patients that will disagree with me on that. I think that this is, like so many things in medicine, evolving. More and more information needs to be gathered, more studies need to be done, and they will probably contradict some of these recommendations. So this is a story that is absolutely evolving, and we've not heard the end of it yet. I know that.
(Interview edited and transcribed by MPR reporter Madeleine Baran)