Random thought on Sun, Tanning & Vitamin D
As I changed races in Me-hee-co last week something I read in Stephanie Seneff's blog post on VitD and sunscreens, etc. that got me thinking about my negative vitamin D experience a few years back. For those who haven't read me drop a comment on it, here's the Cliff's Notes version. I rather foolishly decided to jump on the megadoses of VitD bandwagon a few years back and began taking somewhere in the 5000-10000 IU/day range. I started getting weird "dizzy spells" but only when lying down and shifting positions (like rolling over). I also had my first ever "high" BP reading at my "well woman" doc visit. So I figured I should stop taking all supps and sort that out. I've since added back in the other supps and identified it was the D. I now only take 1000 IU and no more than 2000 IU, definitely not daily (currently I'm experimenting with whether the Estroven is doing anything at this point and it has D in it).
So anyway, Seneff talks a lot about how poorly dark-skinned immigrants from more equatorial regions fair when they move to northern latitudes. The dark skin prevents the sun's rays from penetrating to stimulate D synthesis. So this got me thinking about why we tan at all? I have to think that our ancestors knew enough to find shade/caves/etc. during peak hours of sun exposure and didn't experience sunburn. I doubt they spent several days in a row, as I just did, in the hot sun to maximize the vanity tan (sorry, I'm an unapologetic sun worshiper!) . I don't burn much, I will when I overdo it, and I can burn through a tan if that makes any sense. So while I'll burn less if I've got a base over fresh off the plane, the tanning doesn't have a totally protective quality. Instead, I do wonder if perhaps this was nature's way of limiting VitD synthesis to avoid excessively high levels. IOW, large doses of D may be indicated and effective for those who are deficient, but folks living closer to the equator are darker skinned than those living nearer the poles. It seems a reasonable hypothesis that skin pigmentation evolved/adapted over time so that VitD wasn't synthesized in limitless quantities based solely on one's exposure to the sun, but rather pigmentation may have some correlation to one's D status for seasonally appropriate sun exposure. I know there is some literature on excessive levels of VitD, but I haven't had much time to look into that. It certainly seems we humans have a mechanism by which to limit our own synthesis.
I imagine paleolithic and even up through fairly recent neolithic times this was not an issue. I think I belong somewhere quite South from where I live. Unfortunately aging parents not planning to move anytime soon (or ever) make that not probable any time soon.
Interestingly, total cholesterol seem to have a significant effect.
Besides, just guessing but you'd probably run out of some enzyme or the lanolin-like substrate, as a limiter. E.g., if you want to make D, then don't scrub yourself in the shower right beforehand. Make sure you're not deficient in Mg, either.
Interestingly I tend to tan right through sunscreens. I put anywhere from 15 to 85 on to prevent burning my eyelids, lips, nose, knees and tops of feet. You'd think I'd be striped and mottled but I have an even tan. Hmmph ;)
"A significant correlation between the changes in both systolic and diastolic blood pressure and the increment in plasma calcium was found."
"Moreover, the hypertensive response to elevation in serum calcium was more common in patients with advanced renal failure (serum creatinine more than 4 mg/100 ml). The observations show that acute hypercalcemia can cause an elevation in blood pressure, and renal failure may predispose to such a hypertensive response."
IIRC, a 'creatinine clearance test' would catch a kidney problem before it shows up in elevated 'serum creatinine'.
It hurt your arm because the pressure being exerted was so high.
Also, current thinking the last I know is that chronic diastolic is largely irrelevant, when less than 100 or so - especially for those over age 50 but very possibly also for younger ages.
A cuff + stethoscope might run <$20.
When I hear that lifeguard thing, I always think of how LCers would claim that gladiators gained fat to protect themselves from sharp points of swords and spears. Hey, in our modern day Kevlar is expensive, so maybe people can protect themselves by wearing slabs of bacon :) Except when a gang of neighborhood cats gets you, or course.
We live in a world where much of the environment is artificial in a way that limits access to nutrient absorption. Plastics/industrial contaminants, staying indoors all day, high levels of insulation, poor diet choices, etc. It's all well and good to say 'probably shouldn't be doublefisting 20k IU each day', but many would probably benefit from a small amount of supplement in regions where adequate sun is only available a couple months of the year. Yes, your body stores something for the winter/fall, but up in the PacNW, it's clearly not enough. The previous Natives living here travelled a fair bit, kinda chasing the sun, in more than a few instances.
[i normally comment under paleotwopointoh, but this no longer works]
When supplementing with D3, reduce calcium intake & increase magnesium intake. Eat fermented foods to get K2.
I think it is too easy to overdo supplements(except magnesia for an obvious reason), and your description of your negative experience is raising awareness of a danger to do so.
We found her some Vit D drops (it is wise for her to take some--she's never outside and this is AK) and those seemed not to have the adverse effect so much.
; ( I REALLY am serious about this ... like Taubes trying to "opt out" Evelyn before his book release or the vegetarians conspiring to get any mention of Denise MInger off the China Study's wiki page.
I've had several patients develop problems with Vitamin D3 supplementation, so now I rarely recommend regular supplementation above 1000-2000IU a day without monitoring. I aim for a 35-50 blood level. I have found about a zillion super low Ds and I usually recommend 4000 IU daily and monitor calcium for them. Literally 1/3 of the people I test are below 20 and when it drops below 10 you can see it on their faces. (I know that sounds weird but there's a particular droopy, pale look, somewhat similar to a hypothyroid look but all the labs are fine except ultra low D, like 4 or 6).
I take 5000 IU + K2 and magnesium in the winter twice a week. In the summer I don't bother.
with celebrity endorsements!! So it must be good!!! Ornish and Agatson? Huffington and chicken soup Canfield??
Apparently also with Hyman selling associated supplements, and I'm sure they're reasonably priced. Kinda sure, anyway.
This is what Denise Minger wrote recently at MDA:
In case you’re skeptical that observational studies can run disturbingly contrary to reality, look no further than the hormone replacement therapy (HRT) craze that peaked a few decades ago. By 1991, 30 observational studies—including this one based on none other than the Nurses’ Health data—collectively showed that women taking estrogen seemed to have a 44% reduction in heart disease risk compared to their non-hormone-replacing counterparts. Naturally, this led literally millions of women to jump on the estrogen bandwagon in pursuit of better health and longer lives. A very unfortunate oopsie-daisy sprouted up later when some randomized, controlled trials finally emerged and revealed that rather than being protective, hormone replacement therapy actually increased heart disease risk by 29%!
Also this paper seems to be interesting: http://leda.law.harvard.edu/leda/data/711/Rothenberg05.pdf
D3 increases calcium absorption, so you don't need to take supplemental calcium if you're eating meat & veg & drinking hard water.
If your tooth/bone density is low, take K2. In 2003, my lumbar spine density by DEXA was -2SD (osteoporotic). I added 15mg/day of K2 to my supps. By 2006, my lumbar spine density by DEXA was -0SD (normal). I was told that it was impossible for bone density to increase by that much in that time. GP's & Endocrinologists don't know anything about the carboxylation of osteocalcin in Matrix Gla Proteins!
My mum & I take 5,000iu/day + no supplemental calcium without any problems. 5,000iu/day is ~50% of what our bodies can synthesise from sun-bathing. Are our bodies trying to kill us by synthesising up to 10,000iu/day?
McDougall's stance on supplements in general is what attracted me to his diet back in 2007. He didn't peddle supplements and the only one I have heard him recommend is B12. And that is only if you are strict about his diet (which I'm not).
I find the "halflife" of sun-produced D v. supps interesting. So as Lerner says, I must be running out of substrate or the reaction is limited by product (more likely?). As a kid I was outside as often as I could be, shirtless in summers until I was too old for American standards. I had summer jobs as camp counselor, swim instructor and life guard. My parents took us to Florida in January where I got tan (that I could show off during gymnastics season ;) ). I always feel wonderful when I get me my sun. Indeed my first real brush with SAD was the first winter in college when I didn't go away -- and didn't go away in cold months all through. Also, as I struggled with weight, I wore more and more clothing in the summer. The first bathingsuit pic in the About was the first time I wore one (2007) in about a decade. If I can't get away and it's too cold, I go to the tanning booth. It does wonders for my complexion, mood, basically everything.
But too much exogenous D clearly doesn't agree with me.
Perhaps in the winter I might get a bit D-ficient as I don't handle cold well ... which is why I try hard to go away in January. But this year I couldn't resist having the coinciding Spring breaks!
My youthful experiences with the sun were abusive. I hated wearing sunscreen (still do) and burnt myself badly many times. I also have many of the risk factors for skin cancer; fair skin, blonde hair, blue eyes and of course the previous sunburns.
It caught up with me in 2000 when I had a large basal cell carcinoma removed from my forehead and again in 2003 when more popped up in the same location as the first surgery. My dermatologist had me afraid of the sun and I took all the recommended evasive maneuvers. By 2009, when I completed my first triathlon, I had a different attitude.
I did my outdoors training either in the early morning or later afternoon when I could catch the less intense sun.
My first triathlon was a sprint in August of 2009 in Virginia. It started midmorning and I crossed the finish line early afternoon. I went the entire time without sunscreen and was surprised afterwards to find that I was only slightly pink and no peeling. So sunscreen is one item that I don't worry about for triathlons. I also did a half ironman in November 2010 in Wilmington, NC. I was nearly all day in the sun under a clear sky and no burn.
I believe that my diet and maybe the physical exertion allow this to work for me.
the only one I have heard him recommend is B12.
That's close to what I'm doing (almost no supplements, a multi mineral one or 2 times a week).
But even if I eventually agree with McDougall in the end I would still question his process because his reasoning appears ideologically motivated.
Fixing the result before the analysis taints both the analysis and the result.
No arguments here on your process observation.
anyone with MD after their name should get a serious beatdown for publishing anything about diet. or maybe it's a self-selection problem up front in that people with Wheat Brain are more likely to apply to med school & then go on to pen diet books.
If estrogen HRT -> increase CVD, this is consistent with a role of excessive NEFA release from fat. Interesting ...
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