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Could a Vitamin D Supplement a Day Keep the Colds Away?

At this point, if you are someone who is interested in supplements and vitamins, you might be getting tired of hearing about all the extensive virtues of vitamin D.
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At this point, if you are someone who is interested in supplements and vitamins, you might be getting tired of hearing about all the extensive virtues of vitamin D. But, if you are someone with lung disease like asthma or emphysema, or if you know of someone who has issues with recurrent respiratory infections or lung disease, you may want to still tune in to the topic of this article.

What is the topic I want to write about today? It is about how vitamin D is great for lung functioning and immune support... courtesy of a patient I saw this week in my clinic who wanted to know why her primary care doctor didn't want to check her vitamin D level when she read in an article that it's good for her asthma.

So, let's start with what research shows about vitamin D in regards to its impact on respiratory infections, especially in those who have chronic lung disease like asthma or chronic obstructive pulmonary disease (COPD). In several studies, we have seen clinical evidence that vitamin D may be helpful in regards to having fewer respiratory infections, especially in those with lung disease. However, for the sake of time, we will focus on a large-scale study done by numerous large academic learning institutions and supported by the National Institute of Health.[1]

In a study that looked at those people who had low levels of 25-hydroxy vitamin D below 10, compared to those with levels above 30, those with lower levels were 40 percent more likely to have had a recent respiratory infection. For those who have asthma and levels of vitamin D below 10, they were five times as likely to have had a recent respiratory infection as compared to those who had heartier levels of vitamin D. Similarly, those with COPD with low D-levels were twice as likely to have had recent respiratory infectious issues as compared to those with heartier D levels.

So it appears that all the hype about vitamin D being good for us is not just about our bone health, but may also be phenomenally beneficial for our lungs and potentially good for lowering our risk of respiratory infections. Studies dating back many years suggest a positive impact for our lung health with regards to our friend... vitamin D.

Every once in a while, I still hear from my patients that their primary care doctors aren't checking their vitamin D levels, and they are taking vitamin D on their own because of what they are reading online or in articles. This concerns me on multiple levels.

My first concern is that physicians are still not checking vitamin D despite the research that suggests what a hearty vitamin D level can do for our body. Another equally concerning fact is that patients are taking vitamin D without any monitoring by a professional.

In addressing the first concern, there are many studies that suggest vitamin D has a significant role in our immune function, along with other equally important functions of the body like our bone health and cancer risks. Patients who were vitamin D deficient in studies were at higher risk for cold and flu infections. Those with lung diseases like asthma and emphysema were especially susceptible to vitamin D deficiency in regards to their risks for respiratory infections.

There is some suggestion that vitamin D has an impact on lung functioning. So those with already debilitated or weakened lung functioning, as in those with chronic lung diseases, would be more greatly impacted from a deficiency of this vitamin since it helps to optimize lung function.

With regard to my other concern, despite the great benefit to those with chronic lung disease and those with deficient immune functioning susceptible to recurrent respiratory infections, vitamin D levels still need to be monitored to make sure that you are not taking too much. When you are able to target lung disease using vitamin D with responsible monitoring, the health benefits can be tremendous.

As with any other medicine, vitamin, herb, or food, too much of anything is not going to lead to optimal health outcomes. So, ask your doctor to check your 25-hydroxy vitamin D level as well as your PTH (parathyroid hormone level). These two measurements should help to make sure that you are getting optimal levels for your health goals without taking too much for your body's needs.

The goal is to maximize your levels without causing any negative effects on the side. Also, ask your doctor about what the studies show in regards to the ideal level of vitamin D for men vs. women. Based on studies, there appears to be slight differences in goal targets for vitamin D levels in men and women, and this should not be lost in the management of your vitamin D intake.

So, the takeaway points are that vitamin D really is our friend in many health battles we face with our aging bodies -- including that of our respiratory health. But like with all our friends, you want to check in on your friend to make sure that it is doing well... and that's why you need to be monitored when you are taking your vitamins and supplements. Even if they are good for you, you want to remember that too much or too little of anything in life rarely is a good thing.


[1] Adit A. Ginde; Jonathan M. Mansbach; Carlos A. Camargo Jr. "Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey." Archives of Internal Medicine, 2009; 169 (4): 384 DOI: 10.1001/archinternmed.2008.560

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