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Tuesday, March 20, 2012

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.


Ned Kock said...

Actually, there evidence that skin pigmentation has no effect on vit D production from sunlight:

Interestingly, total cholesterol seem to have a significant effect.

Asclepius said...

Interesting. Did your high BP affect both systolic and diastolic readings?

Lerner said...

I'd think that's a stretch, Evelyn. If you were stuck in a rowboat on the ocean, the ionizing UV would hurt you far faster and far worse than any OD of Vit D would.

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.

Evelyn aka CarbSane said...

Thanks Ned! I'll have to add that to the list of reasons not to consider Seneff's claims too seriously. I kind of took her at her word that something this basic would be easy enough to confirm for someone researching the peer review lit. I tend towards high cholesterol (not "you need statins" high, but when I'm heavier, it's borderline but my HDL is high too). I tend to be noticeably tan like 8 months out of the year the past few years. My doc ordered a D test but somehow it didn't get run. Since she's retired, I'm looking for someone new now.

Tsimblist said...

McDougall is no fan of supplementation in this newsletter article: "Vitamin D: Values for Normal Are Exaggerated"

Evelyn aka CarbSane said...

I don't recall the exact full reading. The nurse took the BP and eyed me strangely when she was like "do you have high blood pressure?". I asked what the bottom number was b/c when I was my heaviest that's what would get borderline high-normal. So I know that was 107, I'm pretty sure the top number was elevated too but not as much. I don't have a whole lot of data points on this b/c I have no reason for regular doctor visits. Something about the fat distribution/size of my upper arms makes BP readings whacky unless they use the larger cuff. The nurse insisted that I was small enough for the regular cuff (yay!) and showed me the line on the cuff and it was actually not a close call, I had room to spare (double yay!), but it hurt like hell when she took it. Both times. It could be a coinky dink. I do know I never experienced that weird dizziness -- that's not even a good word to describe it but I can't think of a better one -- before the VitD or since I stopped taking high doses.

Evelyn aka CarbSane said...

Yeah, probably a stretch especially considering what Ned posted about skin pigmentation and D production.

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 ;)

Lerner said...

"Blood Pressure Effects of Acute Hypercalcemia"

"A significant correlation between the changes in both systolic and diastolic blood pressure and the increment in plasma calcium was found."

but notably:
"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'.

Lerner said...

107 diastolic? Wow, just going from memory that's getting close to a medical urgency (as being lesser than a medical emergency). Btw, if anybody gets high BP and then you have visual disturbances, then that **IS** a medical emergency and so get to the ER pronto and they'll give you nitro or similar.

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.

Lerner said...

Good for McDougall. I have to laugh when I hear that everybody should have levels like a lifeguard :) Though I've mostly worked as a programmer, I've also worked construction - including at a giant nuclear power plant. I can tell you that in summertime, nobody would choose to sit in the sun for lunch. That's nonsensical.

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.

Marie Everington said...

As a dark skinned person living in the PacNW, I will continue to supplement during the moody months because it is pretty obvious to my body when I don't. As with many things, I do try to get as much as I can from sunshine and food, but I am not sure it's so much better to eat 3lbs of salmon per day instead (as if I could!)

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]

Nigel Kinbrum said...

People are encouraged to get huge amounts of calcium in their diets (1000mg+) but are not encouraged to get large amounts of magnesium to go with it. Taking D3 increases calcium absorption, so I guess you're thinking what I'm thinking.

When supplementing with D3, reduce calcium intake & increase magnesium intake. Eat fermented foods to get K2.

Galina L. said...

Since I live in Florida now, my method to get a sun tun consists of walking to the ocean or swimming pool from my car then coming back after a swim. Whatever I do outside I am looking more or less successfully for a shade.
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.

Evelyn aka CarbSane said...

I have never supplemented Ca. I eat a fair amount of dairy but I don't go crazy on that. I had been taking Mg and potassium since before upping the D that time. I eat a fair amount of fermented foods. The chart I just posted mentioned garlic for selenium. Things that make you go hmmmm and it's a crapshoot without diligent experimentation.

Nigel Kinbrum said...

If you have any further problems, it's worth getting a urine test for calcium, to see if you're excreting excessive amounts of the stuff in your wee.

Ela said...

So interesting that you had a negative experience with D! I take 10,000 IU per day, but I live in Alaska and have Mediterranean genetics, so it's probably warranted. My husband's daughter (actually older than me!), who is about the palest skinned person I've ever seen, recently started taking 5,000 IU of D per day, and discovered she couldn't sleep at night when she took it! I thought that was so weird, but now you're the second person with an adverse reaction.
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.

Sanjeev said...

Which automatically makes me thing he's found a negative for his diet & he's putting out some spin before it can damage him. ; (
; (
; ( 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.

Emily Deans said...

Skin color is likely due to sexual selection to an extent, though certainly there is a standard variation of tan from dark to light tan as latitude changes. Excess sun on the skin can destroy folate (I've read) which will be problematic, especially in sub-saharan Africa.

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.

Lerner said...

OT: making the tv rounds is Mark Hyman MD, with "The Blood Sugar Solution: The UltraHealthy Program for Losing Weight, Preventing Disease, and Feeling Great Now!"

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.

Meighen said...

I was tested for D recently and I'm low normal. I thought it would be a good idea to increase it for a few weeks, thinking it probably should be a bit higher. I have a thyroid supplement that gives me the RDA of 400IU's. I was taking 3 calcium capsules which included 600IU's. Plus I was taking 3 D3 of 1000IU's each. Total 4,000IU's a day. I don't know that I realized I was getting that much, or maybe I just thought it wasn't a very high amount (perhaps I was confusing the amount with higher Vit. A amounts people take occasionally, so 4,000 didn't seem like much). Anyway, for a period of about two weeks I had the runs. Had no idea what was doing it - thought maybe too much coconut oil. Searched on Paleohacks for diarrhea, found a posting about D3. THEN I checked how much I was getting, and it was 10 times the daily recommended amount. I cut back to just the RDA (because I need the thyroid supp.) and it went away within a couple of days.

Tomas said...

You mentioned several times that you are taking Estroven. Are you aware of the hypothesis that menopause may actually be caused by estrogen dominance and progesterone deficiency? Estrogen has damaging effects when unopposed by estrogen according to the theory.
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:

Tomas said...

* when unopposed by progesterone

Nigel Kinbrum said...

"I was taking 3 calcium capsules..."
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?

Nigel Kinbrum said...

If you have several deficiencies, fixing just one of them can exacerbate the unfixed ones. So go to a Doctor who knows what they're doing (e.g. Emily Deans) and get them all fixed.

Nigel Kinbrum said...

So fixing one deficiency when there are two (oestrogen and progesterone) results in a bad outcome. Why am I not surprised?

Tsimblist said...


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).

Evelyn aka CarbSane said...

Thanks for this Tsimblist.

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.

Evelyn aka CarbSane said...

Thanks for sharing your patient experiences Emily. If I were more of a supplement taker, I might not have made the connection b/c I was not hearing of any adverse responses.

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!

Meighen said...

The only point I was trying to make was that I was taking too much supplemental D3 for ME, and perhaps help someone else avoid the situation. I have no doubt my body could handle D synthesized by the sun.

Tsimblist said...

You're welcome Evelyn,

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.

Sanjeev said...

TsimblistMar 21, 2012 06:08 AM


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.

Tsimblist said...

Me too. I take a daily multivitamin "formulated for men over 50". Usually daily, but I frequently forget and don't worry about it when I do.

No arguments here on your process observation.

Lesley Scott said...

@Lerner I'm actually attempting to read it right now. The good: he cited - for instance - that study that Evelyn blogged where drastically reducing caloric intake got obese people's pancreas insulin beta cells working again. The bad: The poor Pima were trotted out. *shudder* I'm sure the Kitavans & Inuit are somewhere not far behind, although, he's into those China Study-type observational studies and seems anti-meat, so maybe just the Kitavans. The ugly: the blood-sugar in the title says it all - yes, it's the *insulin as fat storage* fairytale. *sigh*

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.

Evelyn aka CarbSane said...

Welcome Meighen! Yeah, my body too seems to do just fine with lots of sun exposure (who knows perhaps my synthesis is low so I need lots of sun?) but not lots of exogenous D.

Evelyn aka CarbSane said...

This stuff is why I did not jump on the hormone bandwagon. Estroven is soy isoflavanoids and the product really did help me going through meno -- nightsweats and hot flashes (I experienced more of the former), and hubby claimed moods were better (wha? Me? moody? never happened - grin). I doubt highly this type supplement is even remotely equivalent to actual exogenous estrogen.

If estrogen HRT -> increase CVD, this is consistent with a role of excessive NEFA release from fat. Interesting ...

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