Sunlight vs. Vitamin D

[This is part 3 of Epidemiology vs. Etiology]

You may have heard there is an epidemic of low vitamin D levels in the U.S.  An estimated 60% of Americans are at a level that has been correlated with increased risk of nearly all chronic diseases, including cancer, heart disease, diabetes, autoimmune diseases, and depression.  My personal belief is that the epidemiology is horribly flawed.  But perhaps not in the way you might think….

As most people know by now, we humans photosynthesize vitamin D in our skin when it is exposed to direct sunlight.  How fast depends on our ethnicity and amount of exposure.  Since I’m light skinned and get a lot of sun in my normal life, it came as a huge surprise when some routine bloodwork I had done about 9 months ago indicated I was “dangerously low.”

My doctor immediately prescribed large doses of vitamin D supplement, but I was convinced that the result was spurious.  Perhaps it was due to an abnormal period of low sun exposure.  After all, I’d been traveling quite a bit and thus not outside much.  Plus, maybe the jet lag was disrupting my metabolism in some way that impacted vitamin D levels?

I vowed to get my 20 minutes of sunscreen-free, noontime exposure per day.  (Morning and late afternoon sun is useless for vitamin D production, and sunscreen blocks the UVB rays which initiate it).  In addition I intended to eat more oily fish (like sardines) as they contain vitamin D.   Though most experts agree it’s almost impossible to get what we need from food alone, I know that such foods are good for me in other ways.   My plan was to get checked in three months and I was confident that I could raise my vitamin D levels back into health range without supplements.

After three months my test came back… unchanged!  This was very alarming.  The medically acceptable range is between 30 and 74, but I was coming in at 15.  These numbers refer to the freely available levels of 25-hydroxy D in your bloodstream.

A brief aside about vitamin D: it’s not really one substance.  There are many different biomolecules that are involved in a complex cycle that initiates when the sunlight hits your skin.  It’s just a few of the many byproducts of this cycle that we call “vitamin D”.  25-hydroxy D is the one we typically measure, but to focus on this one substance seems unwise given how complex the cycle is.  Personally, I’ve come to think of vitamin D not as a noun but as a verb, as in the “vitamin D process” (with kudos to Danny Hillis for coining this metaphor with the verb “cancering”).

Before I resigned to taking the supplements, I did some googling and stumbled across this video which alerted me to a possibly key factor I was ignorant about: soap.  Turns out that if you wash with soap within 48 hours of sun exposure, you are not getting the full benefit.  That’s because you are washing off the D3 that the sun photosynthesizes when it hits your skin.  And it takes 48 hours to fully absorb into your bloodstream, where it is a critical element in the vitamin D process.  So I switched to the recommended “soap only where the sun don’t shine” strategy.  Three weeks later I got a home testing kit and my count almost doubled to 28.  A month after that, I was within range at 34.

Now, it should be noted that these 25-hydroxy tests (whether performed at home or by your doctor) are notoriously poor indicators of pathology.  Even still, I was advised that with a count of 15 it was very unlikely that I was maximally healthy, even though I hadn’t shown any symptoms yet.  Had my low D state continued, the prognosis is that it was a matter of time before symptoms started appearing.  There is another test which measures functional vitamin D efficiency at the cellular level, and which is supposedly a better indicator.  But that I didn’t know about this test until I consulted with Dr. Myles Spar who is an MD with an integrative/holistic practice.  On that test I scored “above 50th percentile” in vitamin D health.  This was around the time of my second home test, where I scored barely within range at 34.  Thus, according to the more accurate test, I am currently fine, but according to the test that is universally used, I am still in danger and almost all MDs would recommend supplements for me.

For the most part, I’m against supplements, but when presented with possibly serious consequences, it’s seductively easy to justify popping the pills “just in case” they help.  After all, the epidemiology shows very strong correlation between absence of the chemical and presence of disease.  There are two problems with this logic, though.  Almost all bioactive substances become toxic at some dosage.  In the case of vitamin D supplements, they can become toxic even at normally prescribed dosages.

But ignoring the toxicity, there is a bigger problem: taking vitamin D supplements has NOT been shown to reduce mortality.  While supplements reduce melanoma incidence, so does sun exposure.  According to the data, the sunlight effect is so powerful that even sunburns may reduce your chances of dying of skin cancer.  Also, vitamin D supplements don’t appear to prevent autoimmune disease, whereas sunlight does.  Finally, obesity is doubly-linked with depression, which is correlated with lack of sunlight.

What does all this mean?

Here is a partial list of lessons I’ve learned about how complex systems theory applies to me as an individual:

  • It’s appropriate to use blood level indicators to diagnose potential disorders, but it’s rarely beneficial — and quite often harmful — to treat such indicators directly with drugs.  I would rather understand the etiology and treat the pathology, not the symptoms.
  • For every manufactured drug there are natural remedies which have been used for thousands of years without the high level of toxicity.  Many of these are at least as good as the drugs even when focusing narrowly on changing blood level indicators.
  • I don’t want to take any substance chronically, whether it’s manufactured or natural.  The only exception would be if an organ stopped functioning properly and its biochemical output could not be manufactured naturally, e.g. if my thyroid was damaged beyond repair.
  • Most of my body’s systems are homeostatic, meaning when they are pushed “out of whack” temporarily by outside influences, they move back to their previous state once the influence is taken away.
  • In homeostatic systems there emerge one or more “set points” (aka chaotic attractors).  If pushed far enough away from one set point, the body naturally gravitates to a different one.
  • The result being that it is often harder to achieve systemic changes than it is to maintain them.  This may be why it is harder for an obese person to lose weight than to maintain a healthy weight.
  • A valid use of drug therapy is for acute conditions, to bring the body back into a healthy homeostatic set point (or stabilize the body while other interventions do so).

Combining these lessons with my own experience and the epidemiology, the vitamin D story is not so mystifying (to me at least):

  • Why did my vitamin D levels drop suddenly and not bounce back once I resumed my normal lifestyle?
  • Why did my vitamin D level double in a short period of time without taking supplements?
  • Is there really an epidemic of low vitamin D?
  • To what extent is this related to sunshine?
  • How does the epidemiology relate to changes in lifestyle trends?

I’ll leave you with a final thought, and I’d be curious what you think.  Could there be an epidemiological tipping point?  One that either already happened, or that may be seen in the future?  How would we look for such an effect in the data?   How would we tell if it’s a true effect, or just something that we sought to discover and then used faulty statistical reasoning to “prove”?

  • D-Answer

    First, you need a UVB meter when using the sun for vitamin D production. You enter your skin type, it measures the amount of UVB hitting the ground and tells you how long to expose more than 40% of your body without sunscreen.

    Two, serum vitamin D has a circadian rhythm. When you take the blood sample is critical. The low is in the morning, the peak is between 3-9 PM.

    Humans are not unlike horses when it comes to serum vitamin D;

    http://www.google.com/url?sa=t&source=web&cd=2&ved=0CBkQFjAB&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC479703%2F&ei=UsLfTLrVJoyXnwf31uDtDw&usg=AFQjCNHqYtNLVtW1bVfoTcjWVTyelqR_CQ

    Third, shift work, bright light at night and magnetic fields seems to disturb vitamin D rythmn resulting in this;

    http://www.ncbi.nlm.nih.gov/pubmed/16596308

    I would suggest you watch all of these videos;

    http://www.ucsd.tv/series/index.aspx?show=show&seriesnumber=520

    Then look at this study which looked at the disrupted vitamin D cycle of humans who stayed up until midnight.

    http://www.eje-online.org/cgi/reprint/146/5/635.pdf

    Lots to learn about vitamin D.

  • Mark

    I take vitamin D-3 supplements to help combat a life long chronic skin disorder (Guttate Psoriasis) which comes and goes in direct relation to the lack of UVB exposure. The supplement alone does almost nothing for my affliction, and I need natural sunlight or phototherapy with wide band or narrow band UVB, which amazingly actually makes me almost symptom free. While UVB IS the culprit behind melanoma, in proper doses, for my affliction, the cure is better than the alternative. There ARE tanning salons who usually have a station or two that have UVB lamps as well as UVA for phototherapy, and its much cheaper than visiting a Doctors office to use his machine. I’m also a ginger, so I got the double FU…sunlight is not my friend. Good luck with your Vitamin D.

    • Rafe Furst

      Thanks for sharing. I believe the evidence shows UVA is the big culprit for melanoma, and UVB is actually protective.

  • What about the fish instead of a supplement? http://www.skincancer.org/oily-fish-your-route-to-vitamin-d.html

    I remember a UCSD conference talk video where they showed convincing correlation between consistent UVB exposure and vitamin D production, and UVA exposure and skin cancer, but I cannot readily find it through D-Answer’s link (help?). I am basing my whole sun exposure philosophy (and hobo lifestyle) on that talk, so I find your initial findings disturbing. The soap bit is extremely interesting on the other hand (very fitting with the hobo lifestyle).

    As a side note – a dermatologist in Belgium recently recommended a fern-based sun-protection-supplement for me. http://heliocaredirect.com/ It’s supposed to give an SPF of 5 or so — I have no idea what it does for vitamin D production. I’ll let you know if turns me purple…

  • Dear Rafe,

    Thanks for a hearty morning laugh: “soap only where the sun don’t shine”.

    I love it.

    One Love,
    Santhan

  • Torsten

    I read the “how complex the cycle is” and watched the Mercola video. The first says “Vitamin D is produced in the two innermost strata” of the skin. The second says showers wash off the Vit D. Aren’t those two mutually exclusive?

  • Paul

    According to _The Vitamin D Solution_ by Dr. Michael F. Holick (who discovered the body’s active form of Vitamin D thirty years ago), it takes an enormous amount of oral vitamin D to be toxic. For example, on page 255: “I like to give my patients 50,000 IU of Vitamin D2 every two weeks, but if they forget, taking 100,000 IU once a month is safe.” … “Vitamin D intoxication will not occur until a person is taking more than 10,000 IU of vitamin D a day for more than six months. Adults who received 10,000 IU of vitamin D a day for five months showed no signs of toxicity.”

    That said, Dr. Holick favors sensible sun exposure (which he calls ‘The Real Thing’) over supplementation. Page 158: “When you are exposed to sunlight, you make not only vitamin D but also at least five and up to ten additional photoproducts that you would never get from dietary sources or from a supplement.” He and his colleagues are in the process of identifying these photoproducts and determining their biological function.

  • brec

    Influenced by a cardiologist who recommended 25-OH levels of 60-70 ng/ml, I started taking 6,000 IU/day a few months ago. My level at that time was 56 ng/ml. After three months, my level was… 56 ng/ml. I reported this lack of result and the cardiologist said, oh, I’ve seen problems like that with the Walgreen house brand (Finest Natural), try Walmart, Sam’s Club, Costco, Vitamin Shoppe or Carlson brands. So for a few weeks now I’ve been taking WalMart’s Spring Valley brand.

    • Rafe Furst

      What’s your basis (other than listening to your doctor) for believing supplements actually do for you what he/she proscribes them for? In all my digging into it I’ve found no evidence for causation, only correlation. See Mark’s comment on this post about his psoriasis.

      Possibly related: what if the “problem” with the no change for you isn’t the brand, but the idea that blood serum levels have more to do with an acutely attuned regulatory system that keeps a certain equilibrium range?

      Personally I think the whole supplement logic is a bunch of crappy science fueled by perverse incentives.

      • brec

        Y’know, I’m in an epistemological funk. I don’t know what to believe.

      • brec

        I’ve been supplementing for 20+ years, and my hair, while graying, is still primarily brown. (I’m 65.) Q.E.D.

      • Paul

        I’m looking through _The Vitamin D Solution_ to see what studies Dr. Holick cites. Amusingly, the first one is non-human: “.. Kirmani, the first lowland gorilla born at the Franklin Park Zoo in Boston. By the time her caretakers reached out to me for help in 2005, Kirmani was on the brink of death. At just seven months old she showed signs of the bone-softening disease rickets and had severe muscle weakness and risk of seizures, making it difficult to suckle and get enough nutrition from her mother’s milk. … Her pediatricians advised administering 400 IU of vitamin D (twice the recommended daily intake for human infants) but it didn’t do much. I suggested they up the vitamin D dosage to 5,000 IU a day, and lo and behold, Kirmani made a full recovery. She won’t grow to be quite as tall and mighty as she would have, because of her brief bout with vitamin D deficiency and resulting rickets, but she survived and is flourishing today. In fact, I was the guest of honor at her first birthday.”

        … Dr. Holick then reports treating polar bears, Komodo dragons and iguanas.