Vitamin D for Flu Prevention?

Your nose drips like a faucet. Your head pounds. Your limbs, your skin, even the roots of your hair ache. Fever makes you feel hot and cold at the same time … Once again, flu season is upon us, and it’s time to get prepared. Especially those of us who have school-aged children or who work in crowded environments are permanently subjected to a barrage of bugs leading to the flu symptoms described above.

While most healthy adults are able to fight off such flu bugs, the prolonged misery and lost days while you have to wait for your body to deal with the intruder should certainly justify throwing every possible measure at them. Have you received your flu shot yet? We at Health by Principle encourage you to consult with your primary care provider and—if appropriate—take care of your influenza vaccination as quickly as possible.

At the same time, there are additional means available for your quest to leave flu season behind unscathed: Recently, vitamin D has been conclusively proven to be extremely effective for the prevention of acute respiratory infections!

Vitamin D Can Help With the Flu?

You may already know that vitamin D is crucial for bone and muscle health, since it promotes calcium absorption in the gut. You probably also know that many North Americans and Northern Europeans are deficient, since the sunlight’s UV rays that the human body needs in order to synthesize this micronutrient is in short supply in these geographic regions.

In fact, in the US and the UK, many foods are fortified with vitamin D in order to combat this pervasive problem.

Several major research studies have now provided definitive evidence that the so-called sunshine vitamin can protect you against respiratory infections, including influenza and the common cold.[1] It does so by boosting levels of anti-microbial peptides in your lungs. These anti-microbial peptides serve as a kind of antibiotic generated by your own body.

Study participants who already had a healthy baseline of vitamin D levels, but also took supplements reduced the risk of catching an acute respiratory infection by 10 percent. However, study participants who were vitamin-D-deficient managed to reduce this risk thanks to supplements by a whopping 50 percent.

Therefore, if you ensure that you receive vitamin D in at least the recommended daily average amount (600 IU for healthy adults and 800 IU for older adults), you not only reduce your risk for compromised bone health, but you also give yourself a significant advantage during flu season. In fact, some healthcare providers suggest that there can only be benefits to exceeding the daily average and to reach for supplements with more than 1,000 IU.[2]

So, how can you get the recommended dose of vitamin D? There exist three ways:

• Sun exposure (difficult to achieve in regions with mostly cloudy winter weather!)
• Foods (fatty fish such as salmon and tuna, milk, legumes such as beans and lentils, eggs, and healthy oils)[3]
• Supplements

Whichever way or combination thereof you choose to meet your needs and to remain healthy during the flu season, we at Health by Principle wish you Happy Holidays—without tissue mountains, grandma’s home remedies, or desperate drug store trips!

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Sources:

- “Vitamin D protects against colds and flu, finds major global study,” Science Daily, https://www.sciencedaily.com/releases/2017/02/170216110002.htm

- Allison Aubrey, “A bit more Vitamin D might help prevent colds and flu,” https://www.npr.org/sections/health-shots/2017/02/16/515428944/a-bit-more-vitamin-d-might-reduce-winter-colds-and-flu

- Sue McGreevey and Mike Morrison, “Study confirms Vitamin D protects against colds and flu,” The Harvard Gazette, https://news.harvard.edu/gazette/story/2017/02/study-confirms-vitamin-d-protects-against-cold-and-flu/

- Adrian Martineau, David Jolliffe, et al. “Vitamin D supplementation to prevent acute respiratory tract infections: Systematic review and meta-analysis of individual participant data,” The British Medical Journal, 2017; i6583 https://www.bmj.com/content/356/bmj.i6583

[1] There exist many different, earlier research studies on the effectiveness of Vitamin D for the prevention of cold and flu, with sometimes conflicting results. A consortium of 25 researchers at 21 institutions worldwide collected and pooled these data (now counting more than 11,000 study participants), in order to re-evaluate them for more conclusive results. A summary of this research study can be found here: “Vitamin D protects against colds and flu, finds major global study,” Science Daily, https://www.sciencedaily.com/releases/2017/02/170216110002.htm The study itself is also accessible online: Adrian Martineau, David Jolliffe, et al. “Vitamin D supplementation to prevent acute respiratory tract infections: Systematic review and meta-analysis of individual participant data,” The British Medical Journal, 2017; i6583 https://www.bmj.com/content/356/bmj.i6583

[2] According to the Institute of Medicine, adults should cap their Vitamin D intake at 4,000 IU. Allison Aubrey, “A bit more Vitamin D might help prevent colds and flu,” https://www.npr.org/sections/health-shots/2017/02/16/515428944/a-bit-more-vitamin-d-might-reduce-winter-colds-and-flu

[3] See the Vitamin D Fact Sheet at https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/#h10