> Early epidemiologic research showed that incidence and death rates for certain cancers were lower among individuals living in southern latitudes, where levels of sunlight exposure are relatively high, than among those living at northern latitudes
An obvious problem is confounding variables, this isn't a controlled correlation in any way. The article goes on to say:
> However, additional research based on stronger study designs is required to determine whether higher vitamin D levels are related to lower cancer incidence or death rates.
While attempting to understand the link better, UW-Madison researchers recently produced data implying that the ingredients of some sunscreen products may provide benefit in preventing MS.
Edit: I suppose that’s decreased health span more than decreased life span
(Note: EPIC studies Europeans.)
I can't personally vouch for its accuracy though.
I'm not sure if there are studies that take this variable into consideration. The tin foil hatter in me tends to think the results are probably different than the current common belief. BUT we can't have sunscreen sales dropping to zero ;) BTW I'm also weary of the effects of sunscreen itself - does slathering chemicals on your skin to protect against sun contributing to cancer?
Th truth is there is probably a happy medium somewhere between the "sun is evil! It causes cancer!" and "don't worry worshipping the sun is OK". However we tend to knee jerk react in one direction or the other...
you need to compare not the whole populations of geographies - you nee to look at people who isn't evolutionary adapted (in this particular case - skin color to manage the sunlight and vitamin D level in particular) to the geographies they are currently living at.
For example, children autism is much higher in the Somali immigrant population in Minnesota and Sweden (vs. Somalis in Somali) as this immigrant population has, for obvious reasons, extremely low, frequently almost non-detectable, vitamin D levels.
If cancer rate has negative correlation with vitamin D levels, we'll, unfortunately, see it for sure in like a decade or 2 in those immigrant populations.
Some important factors on receiving Vitamin D from sun exposure are skin color, the amount of clothing you wear & time of day.
Light skin absorbs more than dark skin. Noon gives more Vitamin D than morning or evening. Sun screen & sun screen lotion limit the Vitamin D you get.
Being a fellow northerner, walking outside doesn't do much in the winter when 95% of my body is covered in clothing.
Science Vs did a great podcast on this - https://gimletmedia.com/episode/vitamins-supplements-worth/ (Vitamin D is their first supplement they discuss & the link provides a transcript for skimming)
My personal experience (with no medical background except the Chiropractor's wife who recommended it) finds that Vitamin D supplements (5,000 IU) seems to help prevent & shorten colds & flu-like bugs. I mostly take that dosage when feeling slightly ill or run down.
In my experimentation, it takes about 5000-10,000 IU per day supplementation + outdoor sun exposure 3 days a week for about an hour each day for me to be in the (or what I am hoping is) normal/optimal range (around 60-70 ng/mL). My sun exposure in that hour is hiking outdoors in full/partial sun mid-day with no shirt on. So 75% body exposure I guess? I am assuming that normal or optimal is mid to upper values in the lab results ranges for Vit D. In the case of Labcorp, the range referenced was 30-100 ng/mL with anything around 30ish and under being definitely deficient according to the lab results description of the range. So in my case it does take quite a bit of sun + supplementation to get optimal. Now my results above are based on summer sun exposure. In the winter, obviously that will be reduced (colder less outdoor skin exposure + sun is low in the sky) so I'm curious to see what difference I see on the labs without the sun exposure part.
There are some nice phone apps that helpful in figuring out sun exposure and Vit D. I have used D Minder on the iPhone. You punch in some stats about yourself (skin type, age, % of skin exposure and it asks you a few questions to confirm skin type based on your experience in the sun (do you burn easily, just get red and tan, just tan etc). Then based on your current geo location, sun angle in the sky (winter vs summer and the time of day) and time you want to spend exposed to the sun it calculates Vit D absorption in IU. Granted I'm not sure how accurate it is, but based on my labs and supplementation the biggest eye opener to me was how much sun it really takes to make a difference between deficient and normal/optimal. I do tend to believe now that the old recommendation of "15 min in the sun per day is enough" is false. That might be enough to stave off rickets, but I think more is probably in order for optimal living.
However, with all this said it would be great if there more studies on what the optimal or disease preventing blood levels are - with emphasis on blood levels and not just IUs intake per day.
Even if you were naked it wouldn’t help, the sun would be too low.
I do have extremely pale skin, but I yeah, a lot of it ends up covered in the winter.
The major advantage here is cost of living is so much lower than the valley. Housing is cheap, which leaves a lot of room for money to use to eat out, nightlife, plays, music, etc.
Vitamin D defficiency is really a problem, I didn't know I had it till I got a blood test. I was feeling tired all the time, my bones ached, I felt low, dizzy, etc. Getting Vitamin D supplements helped cured all the symptoms, I feel much healthier now.
Of course, when it comes to fish, and especially with concern to mercury, over-doing it is very possible.
For anyone who understands Swedish this presentation is valuable: https://youtu.be/syRaJVIBNnw
Article with the same info: http://www.lakartidningen.se/OldWebArticlePdf/6/6279/LKT0711...
From what I recall the season is from mid October to mid March. There's a few Vitamin D online calculators about if you're curious about where you live, also.
That being said, I really enjoy the fact that scientists are following so many rabbits in the war against cancer. This is going to pay huge dividends on the long run.
Do you have a source for this claim? In America, while not in the Southern Hemisphere, the CDC's Obesity Prevalence maps  show that obesity is concentrated in the southern states.
2017 Fattest Cities in America :
1. Houston 4. Memphis 5. Tampa 6. Las Vegas 7. El Paso 9. Los Angeles 11. Tulsa 12. Miami
NOTE: Steve Gibson is a security researcher and software developer, NOT a doctor, so take the page with a shaker of salt.
Every time someone mentions the man someone says "hurr durr XP raw sockets something something" and links to that page that calls him a charlatan or snake oil seller.
I got results right away last time I had a cluster. I am crossing my fingers that this is it.
This is a very very low amount of exposure to the sun, isn't it (esp depending on your latitude)? I'm asking because it sounds like you're phrasing it as if you think it's a decent amount.
It's honestly only recently that I'm realizing how little sun exposure most people enjoy/are used to. I feel like something's wrong if I don't get sun+fresh air much more frequently than you're describing.
In a bathing suit in Mexico in summer, a fair skinned person will produce their entire daily allotment in just a few minutes.
But that same person with pants and short sleeves might need an hour or more in Michigan in spring.
EDIT: Wanted to mention that a Vit D test is usually around 30-50 bucks, so not too expensive
Some say 60-80 blood serum level is the optimal (80+ is possibly toxic) while others point to 40-50 as healthy
I worry that some people just read a headline and can't cope with details (or don't remember) and end up ignoring the initial good advice.
there's a reason why 99% of australia knows the word melanoma.