November, 2010

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 …

“Freudian Value Semiotics”

Medicine 2.0

Kim Scheinberg sent me a great article from The Atlantic that relates to my multi-thread rant on epidemiology.  Since the article speaks for itself, I’m just quoting points I think are salient.  The only words below that are not a direct quote are the headlines (i.e. “Did you know?”).  The emphasis is mine as well.

Did you know?

  • mammograms, colonoscopies, and PSA tests are far less useful cancer-detection tools than we had been told
  • Zoloft, and Paxil were revealed to be no more effective than a placebo for most cases of depression
  • staying out of the sun entirely can actually increase cancer risks
  • taking fish oil, exercising, and doing puzzles doesn’t really help fend off Alzheimer’s disease

Medicine has caught a plague

we think of the scientific process as being objective, rigorous, and even ruthless in separating out what is true from what we merely wish to be true, but in fact it’s easy to manipulate results, even unintentionally or unconsciously.

There is an