Vitamin D Protects Against Flu

There’s been so much information this fall about flu, particularly swine flu, that it’s hard to make sense of it all. But one piece of information that I think gets missed in all the discussion is the importance of vitamin D in preventing influenza infections and boosting immunity. Research is accumulating about the relationship between flu susceptibility and vitamin D levels, and it’s showing just how important it is to keep vitamin D levels in the 50-80 ng/mL range.

Since the flu season is upon us, and especially since swine flu vaccination programs are moving much more slowly than the virus itself, it seems reasonable to hedge your bets and take in sufficient vitamin D to reach the suggested protective vitamin D blood level of 50 to 80 ng/mL 25(OH)D. This represents a vitamin D blood concentration consistent with that obtained from abundant natural summertime sunlight exposure. The amount of vitamin D needed to reach this ideal blood level varies from individual to individual, depending on sunlight exposure, vitamin D reserves, skin color, body fat, age, and the like — and it’s important that you are aware that at this time of year, if you live in northern regions of the country, you can’t rely on sunlight to provide you with adequate vitamin D.

To summarize all the recent data, I have written a new article that details all the new findings about vitamin D and influenza that I encourage you to read. And I encourage you to find out what your vitamin D status is and determine whether you need to find ways to boost your intake.