Does Vitamin D Help Stop Colds?

A recent New Zealand study suggests that supplementing intake of Vitamin D doesn't reduce your chances of catching a cold. Earlier studies have found a correlation between Vitamin D levels and catching a cold. The lesson? The research is interesting, but we can always use more of it.

Picture by Sean Gallup/Getty Images

The new study, published in the Journal of the American Medical Association, tracked the frequency of colds in 322 New Zealanders over 18 months. Half the group received regular Vitamin D supplements; the other half received a placebo. There was no statistically significant difference in the number of colds (upper respiratory tract infections) in either group, the severity of those colds, or the number of days of work missed as a result.

Other research has pointed in different directions. One study of 19,000 by the University of Colorado found people with higher Vitamin D levels were less likely to have respiratory infections. That doesn't contradict the New Zealand study; it's possible, for instance, that people with higher Vitamin D levels had higher levels of sun exposure because they exercised more, which improved their overall health.

Another study of Mongolian children found their risk of respiratory infection was reduced by a daily dose of Vitamin D-enhanced milk. However, that test pool already had lower-than-usual Vitamin D levels, so we don't yet know if the same results would be evident in people with healthy levels of Vitamin D.

Principal investigator Dr David Murdoch highlighted that point in the release announcing the study:

VIDARIS is the first study to convincingly show that vitamin D does not prevent colds in healthy adults. However, it is important to note that very few people in our study had extremely low levels of vitamin D at the beginning. So, our findings may not apply to these people and to children who should now be the focus of further research.

The big lesson? Science is useful because it repeatedly tests the same propositions over time. A single study is a useful data point, but not "proof" of anything absolute. It's the combination of all the different results that gives us confidence in what we know.

In the meantime, taking extra vitamins may not do you any harm unless the doses are ridiculously high, but chances are a healthy diet will give you the same benefits for less expense.

Effect of Vitamin D3 Supplementation on Upper Respiratory Tract Infections in Healthy Adults [JAMA]


Comments

    LOL! Yeah, it doesn't reduce your chances, at least it didn't for me. I take regular Vitamin D on doctor's advice since I work in an office environment and don't get much sun day to day, and I got three colds this year when I normally get 1-2. Hmmm...

    Whenever I get a cold or even just the sniffles I use Garlic & Horseradish tablets. They don't taste nice but they dry up the nasal passages and allow me to breath properly. During cold season, I take one every morning, haven't had a serious cold or the Flu in years. Hmm,. better touch wood now! NO not that wood.. :)

    The best thing I have found is when you get that irritated behind the nose feeling, rug up and rug up well, and keep out of the wind.

    You may sweat your ass off, but it stops it from going further. Sitting in the warm sun doesn't hurt either (which is Vitamin D anyway).

    Also don't take oral Vitamin D, just wear a short sleeve shirt and walk around in the sun for 30mins a week, you will get more than enough from that.

      oral 'D' is fine so long as you use the capsules and not the tablets. the hard tablets are the wrong kind of 'D'. Been using it for years.

        Inappropriate quote of the day, Noddy says, "oral 'D' is fine.. hard..."

          Feeling shame now, head hanging low, much embarrassment, face turning red. Cruel to me, you are, so so cruel...! :)

      Actually taking a vitamin D supplement is VERY beneficial. The "recommended" intake of vitamin D is actually quite low when factoring in the latest evidence surrounding the benefits of Vitamin D (which should be considered a Hormone vs a Vitamin).

      Even sitting in the sun does not fully get enough exposure (depending on distance to the equator, season and skin type). If you use a sunscreen, it blocks UVB rays which are the ones responsible for vitamin D creation.

      I am away from my Desktop so cant provide links atm. But as a start look at a youtube video by Best Price Nutrition. I think they highlighted it in their Crossfit Supplements Video or Supplements for running. When i et a chance (hour or so) i will link some great data on Vitamin D. Taking an additional 1,000IU a day is great, i myself take 5,000IU but thats for other reasons (To assist with already low levels, and to assist in a genetic back condition to help rebuild bone)

      Hope this clears some of it up...

    Another science story Angus? You doing a PhD on the side?

    They assumed 1.6 colds (URTIs) a year? Ouch. Great to see 18mth cohort though - if you study for too shirt a period you miss out on the many seasonal respiratory viruses.

    URTI defined as "the sudden onset of 1 or more of runny nose, nasal stuffiness, sore throat, or cough that the participant did not attribute to allergy". Including headache would likely have captured more viruses as would feeling hot, myalgia and I bet, hayfever.

    Last edited 03/10/12 1:22 pm

    Vitamin D has numerous health benefits, particularly in preventing certain types of cell damage. However, vitamin C is far more effective in preventing colds!

      Vit C not effective. Anecdotal Mike? Indeed.

        Not effective? I said it was effective. Glasses needed? Perhaps.

          Sorry - thought I was clear. VitC is not effective.
          Do you also subscribe to the wive's tale that colds are the result of getting chilled? Ancient history. Data from studies that were without knowledge we have today and were thus flawed. Did you have something non-anecdotal to back up your faith in the efficacy of VitC?

    Lots of anecdotal evidence in the comments here...

    You won't get enough vitamin D from "a healthy diet" unless you eat lots of fish. You need sun exposure or supplementation to get to the experts' recommended levels (~30 ng/ml).

    This a very good study, but it only shows that people with enough vitamin D aren't helped by more vitamin D.

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