Cold and flu season is almost here and people are lining up to get a flu shot. But did you know that flu shots may not be that effective? And that vitamin D can boost your immune system, helping lower your risk for getting the flu and other viral infections?
Vitamin D is a fat-soluble vitamin that our bodies can make when exposed to the sun. It’s also found in fish, eggs and a few fortified foods (such as milk). Since it’s in so few foods, it’s hard to get enough from diet alone. And with our indoor lifestyles, it’s hard to meet our vitamin D needs with sun exposure. In fact, in the fall and winter months, when sunshine is weak and scarce in the northern hemisphere, many of us are severely deficient in this important vitamin.
So is it a coincidence that cold and flu season is also the time when most of us are deficient in immune-boosting vitamin D? That’s one question researchers are now asking. In fact, some even believe that colds and flus are a symptom of vitamin D deficiency.
Vitamin D benefits your health in many ways, but today I’m focusing on its prevention of colds and flus. I wanted to share just a few studies you might find interesting…
Kids and Influenza. A study done in children found that kids who were given vitamin D supplements were much less likely to get influenza A than kids not given supplements.
Common cold. This study, published in the Archives of Internal Medicine, found that low vitamin D levels resulted in higher rates of upper respiratory tract infections (URTIs), also known as the common cold. If you don’t want to read the study, here is an excerpt from it that explains the importance of vitamin D and why we don’t get enough.
“Indeed, vitamin D is involved in the regulation of 1000 human genes and, most relevant to this study, seems to have promise in the prevention of infection, including URTI. Because few foods contain ergocalciferol or cholecalciferol, sunlight exposure is the primary determinant of vitamin D status in humans.However, in northern latitudes, between November and March, there are insufficient UV-B rays to produce vitamin D. Cannell et al asserted that wintertime vitamin D insufficiency may explain seasonal variation in influenza; this argument may also apply to other RTIs.”
Influenza and TB. The abstract for this study, (full article is not free), begins by saying that epidemiological studies have established that vitamin D3 plays a role in the prevention of both viral influenza and tuberculosis. Note that they don’t say that it’s just a theory!
If you prefer not to get bogged down in scientific studies, here are some articles from the consumer press regarding vitamin D and infectious disease.
So what about the flu vaccine? This review article looked at multiple studies regarding the vaccine’s effectiveness and found that the vaccine only had a “modest effect in reducing symptoms of the flu.” It adds that almost half of the studies it reviewed were funded by makers of the vaccine. Draw your own conclusions there…but the author of this research made this conclusion.
“The review showed that reliable evidence on influenza vaccines is thin but there is evidence of widespread manipulation of conclusions and spurious notoriety of the studies.”
All of this is food for thought. You can draw your own conclusions and make your own decisions about your health. But make sure they are informed decisions. Read the studies. Check the sources. And then decide what’s best for you.