Another post to file under “all the rays are actinic”:
[Near infrared light] can trigger cellular activities that restore cellular metabolism, promote blood flow, neuroprotection, and reduce levels of inflammation and oxidative stress. All of these cellular mechanisms can be summed up as “helping the brain to repair itself.”
Here’s a report on a study which measured vitamin D levels of Hadzabe and Maasai individuals living traditional hunter-gatherer or pastoral lifestyles, the data having been collected with an eye toward learning something about what would have been typical during our evolution as a species.
For the Hadzabe the mean was 109 nmol/l and for the Massai 119 nmol/l. These levels are not outside the reference range, but are way above the minimums.
[T]he mean vitamin D concentration of traditional Africans is indicative of the level that would have been typical throughout much of our evolution, and hence, the level that the human physiology would have grown accustomed to over millions of years. Hence, it’s not unreasonable to speculate that such a level may indeed represent optimality…
People not living traditional lifestyles can get enough sun to see similar levels, but probably not if they work in an office, and probably not at all in the winter (unless they live in the tropics).
I had my own vitamin D level measured once. It was 38.5 ng/mL (equivalent to 96 nmol/l) versus a reference range of 30.0 – 100.0 ng/mL (75 – 250 nmol/l). That was in February though, and that level was produced with vitamin D supplementation.
As I was observing just a few days ago, when exposed to sunlight, your skin does a lot more than just make vitamin D. I’m pretty sure that high vitamin D levels are just a marker for adequate sun exposure. Taking vitamin D supplements in sufficient quantity to raise your blood levels high enough to mimic those of people who get enough sun will produce no more benefit than gaming any metric does.
I’d be interested to know what my vitamin D levels are right now, after a long summer of getting plenty of sun. But not interested enough to go to the effort of convincing my doctor that it’s worth testing again, nor interested enough to pay for the test.
I used to make fun of our culture’s weird fixation on dangers from ordinary things, but now that I’ve seen it have its effect on Jackie’s mom (labeled a “fall risk” at the hospital and now confined to a wheelchair), it’s not so funny any more.
My theory is that this phenomenon has its roots in how safe daily life has gotten: Eliminate any particular danger and there’s always the next most dangerous thing.
I have been predicting for years—only partially tongue-in-cheek—that we’re dangerously close to feeling like it’s a “reasonable” precaution that everyone wear a helmet while taking a shower, because bathroom slip-and-fall injuries are probably the greatest non-motor-vehicle risk that ordinary people face.
Hospitals’ fear of elderly people falling is so great that they are preventing them from walking, reports The Washington Post. This is ostensibly for the patients’ own good — yet not getting up for even just a few days is crippling them…
Just as an aside: One thing about this that drives me crazy is that safety advocates have pushed for all sorts of changes to cars to make things safer for drivers and passengers, but I’ve seen almost no push to make cars safer for bicyclists and pedestrians. If you want to make things safer, there’s a place to start.
I try to emphasize “movement” over “exercise” these days, but sometimes exercise is just what I need. So I was pleased to find this blog post on @rynfrd’s parkour site: six foot exercises that look pretty useful: https://parkouredu.org/six-foot-drills/?learn=11
I’ve been giving blood several times a year for a while now. Maybe it’ll reduce my risk of infection, cancer, or Alzheimer’s as discussed in Iron Is the New Cholesterol. Worst case, it’s a very low risk way to help other people.