July 08, 2008

Beyond the ABCs of vitamin lore

[By Merry]
For some reason this flickr photo makes me want to sing "Let the sunshine in!" ...

This is a rant.
It is only a rant.
If this had been a real, informative post, it would have been written by Crabby.
It is only a rant. Please remain calm.

Okay, yes, I get it that vitamin D is important. Hell, it's a vitamin. They're all important from a basic building-block-of-life point of view; that's why they get named after letters of the alphabet. Fine. No problem.

What makes me cranky is the sudden onrush of articles about how essential it is to get outdoors in the sunshine, stop and smell the roses (check first to be sure there's no bee visiting the rose first), and soak up some rays. SOME rays.

Two Points:

1 - Every which way you look, someone is warning about the evils of too much sun.

2 - You need vitamin D, which you can only get from sunshine or supplements, i.e. from putting some effort into ingesting the stuff. You really can't get all the vitamin D you should have just from regular (un-fortified) food. "Vitamin D is found naturally in very few foods."


On one hand, the argument against supplements is that you can overdo. Vitamin D is a fat-soluble vitamin, so, like overdoing the vitamin A, it's possible to get too much of a good thing.

And on the other hand, we've all been warned for years that if you venture out in the daytime hours, you'd better be slathered in the greasy stuff. The problem with sunscreen is that if you wear the stuff, it almost invariably blocks the synthesis of vitamin D on your skin.

Technically, to make vitamin D you have to sweat. As the sun's rays hit the sweaty skin, vitamin D is synthesized in the sweat and then absorbed into the skin. Then the liver and the kidneys get into the act and finally you have the vitamin D that helps build bones and do a whole lot of other good things too.

To keep all the experts happy, you'll need to make sure you either a) get just the right amount of vitamin D through supplements or b)get outside for 20 minutes or so in the early morning or late afternoon without sunscreen, but to make sure you don't get skin cancer, you have to remember to use the greasy stuff if you're going to be out during the main part of the day.

It's a lot to remember. Complicated. In reality, I'll probably guard against the sun most of the time, but occasionally I know I'll forget and go out with unprotected skin, which will then allow me to get some vitamin D into my system. And of course supplement with vitamin pills. Since I forget to take them on a regular basis as well, this means I won't have to worry about overloading my system with the D stuff.

Sigh. One more thing to keep track of when I'd rather be off having fun in the sun or becoming a slug in a hammock.

Okay. Rant done.

Do you make a point of taking vitamin supplements or making sure you get juuuuust the right amount of non-sunscreened exposure? I would think for people in the more northern climes *cough* Canada *cough*, it would be really challenging to get all the vitamin D the experts say you should have without resorting to hitting the vitamin bottle or taking the odd vacation to Cancun in December. And January. February, too.

What do you do?


  1. The whole thing is frustrating, I mean, define "some" sun! Do I want weak bones or skin cancer? Hmmm...
    Personally, I always take a Vit D supplement. MS creates a situation where no matter what, I am deficient, so at least I don't risk the "overdoing it" part. As for sunscreen, if I am going to be in the sun for a while, or exposing more than shoulders and face, I slather. If I am going for a 30 min walk on my lunch break, than no, I let the sun do a little a damage and my body (hopefully) process a little of Vit D. But the whole thing bugs me. To have experts who have been painting the most terrible picture when it comes to the effects of sun exposure turn around and announce that we actually need to get in the sun "some". Pff. Get out of here.

  2. Ah yes, Crabby writes the informative posts, with extensive research citations on important topics... like, um, lets see... well, ok she doesn't. She's more likely to bitch about gym equipment or complain about the lack of toilet facilities in the Great Outdoors.

    So I totally concur on the Vitamin D frustration/confusion, since it's REALLY important to get enough (cancer, MS, and all kinds of stuff are linked to deficiencies) but also possible to get too much sun (cancer again) or too many supplements.

    I use the half-assed approach: I supplement a little and sometimes "forget" to put sunscreen on my legs when I go running in the mornings.

    I also saw a study once that tested people who live in Hawaii, some of whom did not regularly use sunscreen, and guess what? Some of them were vitamin D deficient. In Hawaii without sunscreen!!!! So even if you risk skin cancer, if you're one of the unlucky ones all that sun may still not be doing the trick.

    Nice rant!

  3. I think Cranky Fitness should do a study. Every winter, Crabby should send us Canadians tickets for a beautiful place down south in the Carribean (but I'll settle for California, Arizona or New Mexico), for a month or two. Then, in 10 years or so, we'll evaluate our health.

    I'll volunteer to go. ;-)

  4. I refuse to use sunscreen in Canada. On vacation I will, but at home? Nope. I want the sunshine. Vit. D supplements make my heart race and not in the good way either.

  5. This post made me think about Cornell, where the students are prescribed natural spectrum light boxes for their winter depression. And no, I'm not kidding. Sunlight makes your brain produce happy chemicals, but too much is bad for your eyes.

    Sorry about the unrelated comment.

  6. I do sunscreen daily and then fret not about how much Im outside (well not daily...I do reapply) that said I constantly am rubbing my eyes as the sand gets in there from having my head shoved down in it.
    there are so many studies to read I get all kinds of confused...so I just do what I can.

  7. I'm with Marijke. Send me somewhere warm!

    Mostly, I wear sunscreen because I have red hair and fair skin and I don't like being sunburned. But that only works when I am thinking ahead and planning on outdoor activities.

    Say it's a sunny weekend morning and I run outside for something that is meant to be quick...then I get distracted and end up poking around in the yard with no sunscreen...Sometimes I do go out without sunscreen. But I do try not to overdo it, again, because I don't like being sunburned.

    I am not a big vitamin taker, but I take a Calcium-Magnesium tablet every night before bed (restless leg syndrome), and I try to get the ones that have vitamin D in them.

    It seems like there is only so much you can do without making yourself crazy.

  8. when I had to take my exercise hiatus, at the same time i decided to quit taking my myriad of pills. Even my multi. I dunno, it just feels better to just eat as healthy as I can and not try and singlehandedly keep the supplement industry in business. It's a new thing for me:)

  9. I like Marijke's idea! All of us Canadian readers could converge on a beach somewhere down south for a month, every year for 10 years.... and see what if does for our Vit. D levels. :)

  10. when i took a nutrition class while in college in boston, we were told that people can't always get their recommended vitamin d from the sun ... which i totally understood given that you didn't see it for a month at a time sometimes (oh wait! i see a hint of it behind a cloud! will it peek through? maaaaayyyybbbeeeee ... no. darn.).

    i tried to take a multi, but that's about it. i know, i'm bad.

  11. I guess I'm just lazy, but I don't use sunscreen unless I'm going to be outside for more than an hour or so. I also have olive skin from my Greek heritage, and I've only ever had a sunburn once in my life.

    All this vitamin D vs. sunblock stuff just confuses me. Do we have to pick between two evils? Low vitamin D levels or possible skin cancer? Then theres the question of cancer from the chemicals in sunblock anyways?

    Well I'll stick my usual ways and take the middle road. I'll use sunscreen for my time at the beach or lots of yardwork, and no sunscreen for my daily activities like a run or doing errands.

  12. About the Hawaiian study -- I understand that people with darker skin are less likely to sunburn but also less able to synthesize vitamin D on the skin.
    What confusing me is that Eskimos (Inuit? Whatever term one uses these days) are /not/ as likely to contact MS as are Canadians of European ancestry. If vitamin D is behind that, there must also be some other genetic factors at play as well.

    Crabby? Think you could find us a sponsor to send a horde of Canadians to Cancun? Purely for research purposes, of course. It warms my heart to see how devoted some people are to Science ;)

  13. One encouraging thing about the vitamin D/skin cancer debate is that this is one instance where it actually pays to be a little forgetful sometimes. If you forget to take your vitamin pills one day, and forget to wear your sunscreen another, but do pretty well on both most of the time, then it looks like you'll be doing okay :)

  14. I'll keep it simple... Damned if you do, damned if you don't!
    Enough said! =)

  15. All of these conflicting studies and warnings just prove one thing.. we read too much. I only slather on the screen if I know I'm going to be out and exposed to intense sun for a significant period of time. I only take supplements if I feel I've really been slacking in what foods I've consumed recently.

    That having been said, I'm still willing to be a part of your Canadians and Vitamin D study. ;)

  16. I have pretty much given up worrying about stuff like this. I just try to act as much as possible like a human animal. I.e., do what I want and don't obsess about the flibberty-gibbet that is The Latest Nutrition News. I take a multivitamin when I remember to, but only one (you're supposed to take two of these a day) just because I kind of don't like the idea of having to take vitamins. My bone density tests have been fine.

    I use a moisturizer on my face and hands that contains sunscreen, but really only because I'm vain and don't want wrinkles and sunspots. I'm hardly ever out in the sun except for short walks to the bus stop. Not a beach person.

    But don't listen to me, I'm a fitness idiot. Why I even read this blog it's hard to say, except that it's friendly and funny. And I hope that by reading it someday I'll be inspired to get off my butt.

  17. I never used to take vitamins, because I'd look at the label and it was 300% of this, 500% of that. Even if it's water soluble, I don't see the need to take more than 100%. But I did find one (and chewable and tasty no less) that I keep at work and have built into my routine to eat after my snack every day, along with my yummy omega-3 chew. I don't take it on weekends, so I hope that balances out if I do ever get too much of something. Whatever, I don't pay close attention.

    I've got blond hair and my skin has two colors - white and red. Tan is not in the cards for me. So I live by sunscreen. This summer I haven't used to much, apart from a moisturizer with sunblock for my face every day. I think because this summer hasn't been too terribly sunny so far. I figure, I'm not usually out in the sun for more than 15 minutes at a time, so I'll just put on sunscreen if it's longer or if it's really hot and sunny (like today).

    I'm a recovering slacker with this kind of thing - I've always paid attention to sunscreen, given my skin, but the whole making sure I have enough vitamins thing is new. The divergent studies pulling me in every direction definitely doesn't help. So I just do what I want and hope it's helping...

  18. Agreed! It's so hard to keep up with it all...and I'm allergic to most sunscreens, so basically I'm out of the sun all during midday.

    I've read that some cultures get their vitamin D from fish, especially in the summer months when sunlight is scare. Maybe I'll just eat tons of fish.

  19. Being a bald-headed irishman, sunscreen and I have a very intimate relationship. That being said.. I love being out in the sun, getting a tan. I sometimes don't know my limits, but I ALWAYS have sunscreen on!
    As for vitamins.. I do take some supplements, for other benefits. I used to take a multivitamin, but like you after reading too much, I came to the conclusion that no one pill can fulfill everybody's body need for every vitamin. LOL

  20. I don't use sunscreen nearly as often as I should. I'll apply it when I know I'll be out in the blazing southern sun for over an hour, but for everyday stuff, I blow it off. I have olive skin, but I can still burn. That being said, this is the first time in years that i have even a bit of real tan on my legs thanks to my running shorts, and I have to say I like it.

    One time I definitely don't wear it that could be questionable is on my long runs. Yes, I'm outside for at least 90 minutes, but I'm sweating so profusely (think water fountain) and wiping my face & neck, I'm not sure there's a sunscreen that would survive. Anybody tried anything that works?

  21. As a Canadian - south central Ontario, actually - I just have to point out that we get a lot of heat and sunshine in the summer months. Today is 27 celcius (about 84) but with the humidex, we are looking at more like 104.
    In fact, there are parts of Ontario that are in the same climate and growing zone of that of the Nappa Valley! (Just had to clarify that - we don't have winter all the time, here!!)

    I wear sunscreen, for the most part, but I will admit it - I like the way my skin looks with a good ole tan. Often times there are just too many 'reports' to know what is credible or not!

  22. Honestly - I think just getting some sunlight is enough. Your body will not come down with skin cancer if you're out for 20 minutes or so in a day - we're not made to live in caves all the time. Moderation in all things I think.
    I find walking about half an hour will do it - my walk or bike ride to and from work is usually enough for me. I'm a pasty lab rat, and don't like the sun. Too much vitamin D is not that pleasant...hot and sweaty and crampy (for me anyways). I don't like vitamins for that - a bit of sun will do you. Not enough - well you get moody and aren't as healthy. I just figure I do what I can and forget about it.

    I wonder if you could just get one of those "mood" lights for people who get SAD and get the light that way?

  23. The Protein Power Lifeplan by Dr. Michael Eades has a wonderful chapter on Vitamin D and sun exposure... I highly recommend it! (And the whole book for that matter...)

    Apparantly our body cannot regulate the absorption of Vitamin D that we take in supplement form, so by taking supplements your body will continue to store the vitamin even when it doesn't need it. Excess stores of Vitamin D in the liver can actually be toxic. Also, sun screen blocks UVB rays rather than the harmful UVA rays that cause skin cancer. So... ideally you would just want to limit sun exposure to what your skin can handle without burning, then cover up. If you're light-skinned and burn easily it doesn't take nearly as long to absorb Vitamin D so it all works out!

  24. its ridiculous really. the doctors are contradicting themselves.

    I honestly think that since you live farther up north you might want to consider supplements or *gasp* not wearing sunscreen everyday, or maybe when youre just outside for long periods of time.

    I used to live in the portland, or, area and almost never got burnt. I now live in the kansas city area and cant spend more than an hour outside w/o getting burnt if im not wearing "the greasy stuff".

  25. Most of my genes are Scotch-Irish, so if I am out in the sun for a long time (hiking, by the beach, working at summer camp etc), I will burn. So I am pretty careful. I sit under the umbrella at the beach.

    However, I walk to work everyday, total 30 min roundtrip, and only wear sunscreen on my face. If I go out for a bike ride or long walk, I put on sunscreen.

    I also don't take a multi-vitamin but I do eat fortified cereal and loads of fruits and veggies.

    What does this all mean? I don't know! Probably being moderate and knowing your limits is good!

    Oh science, you are crazy!

  26. It's frustrating when it comes to any topic of nutrition...this or that? There is so much contradicting information out there it's hard what to believe.

  27. Well, I'm all for joining the Cancun - Vitamin D study! I wear sunscreen daily on my face year round. When I think I am going to be out in the sun for any length of time I wear sunblock everywhere that is exposed. The key being "when I think".

  28. My best friend is trying to get into medical school and he said he learned that living where we do in Canada, we don't get the amount of vitamin D that we need no matter how long we stay in the sun. All these bits of information coming every which way can be rather frustrating!

  29. Daily intake of D vitamin from sun is supposed to be fulfilled with calcium supplements, but there are also so many myths and facts on this.

  30. In Ireland's North West, we get less than an hour of sunshine a day for a few months in winter. (55 degrees north + clouds = I was one unhappy bunny)

    I wear sunscreen on my face. Wrinkles and all that. But it very rarely gets warm enough that I wear short sleeves here - and putting sunscreen on just my hands just seems silly.

    So I guess I hope I'm getting enough vitamin D via my hands?

    ...I'm going to go take my multivitamin now.

  31. Count me in with the "I wear sunscreen unless I forget" group. It's a very scientific method, IMO. It's also the method I used to apply to vitamins. But when I read that vitamins coming from non-food sources are not easily absorbed (which is why all the labels are 500% of this and 652.123% of that), I just stopped taking them. I eat better now, and I spend the extra money on coffee. What? They say caffeine is good for you!

  32. mega dilemma especially for someone like me who avoids the sun like the plague and has already had three precancerous lesions.So I mx and match the sun screen to the amount of time I think I'll be outdoors and I try to drink vit. D fortified milk.

    Hi Christine, I loved North West Ireland when I visted. In fact I love the entire country.


  33. Sunscreen is one of my soap boxes (hand washing is my other one). I'm for it (hand washing too).
    My skin is very fair, so I wear sunscreen every day. No sunscreen is effective in blocking 100% of the sun's rays, and I'm most likely not covering every part of my skin 100%. So, there's still room for the sun's rays to get through and cause their damage, as well as encourage some vit D synthesis. I take a multi vitamin too, for what that's worth.

  34. Yeah and also, sunscreen has lots of toxic chemicals in it! safecosmetics.org

  35. Yeah and also, sunscreen has lots of toxic chemicals in it! safecosmetics.org

  36. I'm definitely in the fair-skinned group. (When I read Christine's comments I thanked the ancestors for getting the heck out of Sligo when they could -- not that they had much choice.) I tend to go for large hats and thin-but-effective clothing to shield me from the sun, but then I'm allergic to most chemicals out there.
    Waves to MaryAnne in K

    I certainly don't advocate getting more sun than you need. Yesterday at work I was speaking to a co-worker. I'd always thought she was at least 10 if not 15 years older than I am. She is very tan. Turns out she's 1 year older.

    (Hey, if health doesn't motivate you to avoid excess sun, vanity might do the trick!)

  37. Hi, just calling in from the country with the worlds highest skin cancer rate. I read an Australian skewed report on Vit D last summer, which basicly boiled down to a bunch of doctors saying that down here we had nothing at all to worry about. It's amazing how much health has to do with physics.

  38. It is pretty hard to be Vitamin D deficient in Australia, but I live in Canberra where in winter the sun rarely pokes its head out from behind the clouds. In summer I wear a moisturiser with sunscreen normally and switch to heavy duty stuff if I'm going to be outdoors for a while, but in winter I tend to not bother because I'm never outside for longer than 5 minutes at a time if I can help it (by Australian standards its pretty cold here). So I take a supplement once or twice a week during winter to make sure I have enough vitamin D, but no more than that.

  39. Merry, did I read that right?

    Did your family come from Sligo? No shit!


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