Vitamin D: 5 interesting facts

the original vitamin D source for humans

Days are getting shorter and darker.  So our thoughts turn to vitamin D, which strictly speaking is a hormone.  When the more intense rays of sunlight in summer hit exposed skin, vitamin D is formed.  In winter, the sun’s rays aren’t strong enough to create the effect.  And if you spend most of your life indoors or in a car, you won’t ever be exposed to sufficient sunlight.

Vitamin D has been in the news lately.  According to Smart Brief, more than a dozen studies supporting D’s link to health came out in just the past 2 months.  On the other hand, one study claimed that the vitamin was not so special, since it failed to fix high cholesterol in people with heart disease, when given for a short period of time.  The thinking goes something like this: since vitamin D doesn’t act like a statin drug, why bother?  Just take drugs.  Drug companies will thank you.

Honestly, sometimes I wonder whose side these researchers are on.

Meanwhile good news continues to build linking vitamin D status to health.  A study from Spain found that lower blood levels were linked to higher risk for bladder cancer.   Another study found a similar relationship with pancreatic cancer: lower blood levels linked to higher risk.  A study from Switzerland found that elderly human subjects taking 800-2000 I.U. of vitamin D had 30% fewer hip fractures.  And in case you missed it, last Friday, November 2nd, was Vitamin D Day.  I’m not aware of any other vitamin that has an official Day.

In honor of Vitamin D Day, here are 5 random things to know about this important vitamin

  1. People in Tanzania who follow pastoralist lives, outdoors most of the time, have average blood vitamin D of 46 ng/ml (115 nmol/l), ranging up to 68 ng/ml (171 nmol/l).  Their vitamin D levels are strictly due to sun exposure.  In the US, by contrast, a study 3 years ago found that more than half of people studied had levels below 30 ng/ml, which is considered insufficient.
  2. Tanning beds can help raise blood vitamin D, if the light source emits the appropriate UV rays, even before much tanning has occurred.  NOTE: Obamacare imposed a tax on use of tanning beds.  So in other words, Obamacare is imposing a tax on vitamin D.
  3. Vitamin D is not just for calcium absorption and strong bones.  It is involved with gene transcription, controlled by Vitamin D Receptor (VDR), present in over 35 different cell types.
  4. Obesity is associated with lower vitamin D levels.  While the reasons for this aren’t well understood, some experts believe fat-soluble vitamin D tends to hide out in fat cells.  In one study, obese subjects who lost 15% or more of body weight had a significant increase in blood vitamin D.
  5. Highest vitamin D food?  Cod liver oil, with 1360 IU per tablespoon.  Vitamin D occurs naturally in just a few foods, most of animal origin like oily fish.  Foods like cereal may be fortified with added vitamin D.  Dairy foods are also fortified with vitamin D.  Because most vitamin D foods are animal origin, vegans must find suitable vitamin D fortified foods or supplements, or risk deficiency.

 

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