Vitamin D: New Data on Reducing Cancer Risk

May 14, 2006

Vitamin D:  New Data on Reducing Cancer Risk 

 Competency # 12 (Old List) #17 (New List) Vitamin D Reference:  Journal of Cancer Epidemiolog Biomarkers. Prev 14. 2898, 2005.   American Journal of Public Health:  Feb 2006 

 You know that Vitamin D is the only Vitamin that your body makes itself.  In effect, that makes it not quite a vitamin, as the definition of a vitamin is that you need it from an outside source.  The outside source we need is sunshine, something sadly lacking for 6 months in Wisconsin.  But now, the Vit D season is upon us.  It’s time to take off the hat and shirt and get out in the sun this coming Memorial Day weekend.  In 20 minutes of sunshine, your body will make 20,000 U of Vitamin D, which it will hang on to and use for about a week.  

Plan on at least 20 minutes of sunshine in midday broken up into 5-minute pieces here and there each week, and you will keep your body in optimal health. And what are the specifics of Optimal Health we are aiming for?  It’s not just bones anymore. 

 Recent references to Vitamin D in the news are the following: 

      1.  From the People’s Pharmacy Radio Show (90.7 at 11 am on Sundays) Walter Willet, Professor of Nutrition from the Harvard School of Public Health, stated that we need to readdress the current amount of Vitamin D in our diets.  Out vitamin pills only give us 400 IU a day. Milk only gives us 100 IU a glass.  He referenced the emerging data that 2,000 IU a day starts to have anticancer effects.  He also referenced that with summer coming, we didn’t need to take it as a vitamin if we could allow ourselves to be sensibly exposed to bright sunshine without allowing ourselves time to burn. (< 15-20 minutes) 

       2.  Journal of Cancer Epidemiology Biomarkers. Prev 14. 2898, 2005.  Research study following 68,000 women found that women in the northern states had a 20% reduction in breast cancer between those who had the most and those who had the least Vit D.  This supports a large European study last year that found similar 25% differences in incidence between Scandinavia and Italy. 

      3. American Journal of Public Health:  Feb 2006.  “Role of Vit D in Cancer Prevention”  Review of 63 observational studies of Vit D and cancer concludes that taking up to 2000 IU a day is safe and has marked anticancer effects across a wide spectrum of cancer. Vitamin D works by making cells mature into fully mature cells of whatever type they were intended to be.  It also works by slowing tumor blood vessel growth, tightening cellular connections, and assisting the normal programmed cell death.   All of these lower the abnormal uncontrolled growth of cancers. 

 WWW.  What Will Work for ME?  The stuff is free!  Park far away from your job, enjoy walking 5 minutes in the sunshine to work and get 5 minutes of sunshine twice a day just in going to work.  I’ve stopped taking my supplement pills.  I’ll get my flowers in the garden this weekend.  And after 15 minutes, I’ll put on a hat and some sunscreen.  If your skin type is darker, you need proportionately more sunshine: up to 5 times as much to get similar D production.  And you don’t have to worry about the skin cancer, like lightly pigmented skin types do.  So enjoy!

This column is written by Dr. John E. Whitcomb, MD, Brookfield Longevity, Brookfield, WI. (262-784-5300)