The Vitamin D paradox.

[powernoodle]

On one hand, there is very strong association between vitamin D blood levels above 40 ng/mL and good outcomes (very low mortality) with Covid infections.  On the other hand, giving people vitamin D prospectively to raise their blood levels of vitamin D prior to infection does not seem to produce the same association.  This is called the vitamin D paradox.

The evidence is increasingly establishing that vitamin D may not be protective.  Rather, vitamin D is a marker that shows that the person has been exposed to adequate sunlight.  And it appears to be that the sunlight itself, and not the vitamin D, produces the low incidence of Covid mortality.  It does this by a number of mechanisms discussed in the first video below which reduce oxidative stress on the mitochondria.

If find this utterly fascinating.

Seasonal flu is also strongly correlated with latitude.  Countries farther from the equator get the flu earlier, longer and worse than countries closer to the equator, and this is true when temperature and humidity are factored out.  This strong association points to sunlight, especially near infrared ("NIR") and UV light, as the causal factor in protecting against flu infection.  To get the benefit of sunlight, you do not need direct exposure or exposed skin, as the NIR and UV radiation penetrates clothing.  They also penetrate cloud cover.

Each to his own, but I am going to try to increase my indirect sun exposure to 30 - 60 minutes per day when possible.  Not necessarily direct sunlight exposure, but enough outdoor activity to increase my indirect NIR and UV exposure. 

[Sea Monster]

Would you believe that this was the driving factor behind both "Lawn Culture" in the USA in the 1800s, and also Tetherball.

Two phenomena that taken at face value seem absolutely pointless, but when seen as a subversive movement intended to trick a population into being outdoors for a certain amount of time each day, make a lot more sense.

[Zephon]

Quite interesting. My kids (whole family to be exact) got Covid Omicron Flu Jan 2022, despite working from home, classes at home (no face to face here in Philippines going 2 years already). Post Covid treatment was a vitamin D supplement for the kids (early teens) but I suspect that it’s the lack of going out for fresh air and sun that contributed to lower immune system even if fully vaccinated.

[Grant Lamontagne]

See, now I have a slightly different Vitamin D Paradox- I work outside every day (construction inspector) but since it is cloudy and/or rainy much of the time I don't really get as much as I could! 

Def

[Aloha]

I also work outdoors but must use sunscreen since its mostly sunny here.  If being in the sun helps then thats easy for me to do plus on my off days I prefer to be outdoors.   

[Altis]

Getting sunshine could also imply some level of physical activity. Often when people are outside, they're on the move in some way... walking, cycling, swimming, doing yard work, etc..

No doubt in my mind at all that sunshine, fresh air, and exercise all do well for your health and immune system. Which makes it all the more wonder they closed down golf courses here last summer... 

[Aloha]

 

Excellent point.  Theres a lot to be said about being outdoors.  Just simply being outside enjoying would also reduce stress levels. 

[pfrsantos]

Excellent point.  Theres a lot to be said about being outdoors.  Just simply being outside enjoying would also reduce stress levels.

Unless you're homeless.

 

Don't mind me. I'm stuck at home for too long... also seeing a lot of Jimmy Carr stand up comedy.

 

[Syncop8r]

Very interesting! A good reminder that correlation does not equal causation.

I remember a debate about Covid restrictions where some compared New York (more restrictive, more cases) to Florida (less restrictive, less cases  and older population?), perhaps sunlight was a major factor? 

[dks]

For me it is impossible not to get enough sunlight.

However, especially for paler people, exposure to the sun does carry risks to the skin and eyes.