Can Your Sunscreen Lower Vitamin D?

Vitamin DI’m not subtle  when it comes to my enthusiasm for sunscreens and the numbers from the Skin Cancer Foundation  support my views:

* Up to age 60, up to 90% of skin aging is actually sun damage

* 5 million people in the US  are treated each year for some form of skin cancer

* The incidence of skin cancer has risen 77% between 1992 and 2006

* 90% of all non-melanoma skin cancers are due to UV rays

* Melanoma is the  most common form of cancer for young adults  25-29

Despite these numbers I hear  many reasons  ( excuses?) for not using sunscreens and most of them are easily refuted.   But then there is the issue of vitamin D.

Vitamin D 101

Vitamin D is an essential nutrient that  has long been liked  to strong bones and teeth   as well as a healthy immune  system.  More recently, research suggests that low vitamin D levels may  increase  risk of a wide range of health problems including diabetes, breast and prostate cancers and  high blood pressure.  We can get vitamin D from  oily fish like tuna and salmon, but  most of our natural  vitamin D is actually maufactured  in  our own skin.  When exposed to sunlight, the body  can convert  a type of cholesterol into active vitamin D.  And it takes very  little sunlight  to get the job done.   For  most people as little as ten minutes a day  will provide the body  with  the necessary amounts of vitamin D.  In fact   additional  exposure will actually  start to  destroy the   newly formed vitamin D.

Vitamin D and Your Sunscreen

Some  health gurus are now  warning that  by blocking  UV rays, sunscreens  put  us at risk of vitamin D deficiency.  Not true.  To begin with, sunscreens are   just not that effective.  Most of us  put on sunscreens in the morning and forget about them.  In truth, most of the effectiveness of the sunscreen wears  off in less than two hours  and few of us  are diligent enough to reapply them.  Even if we wear a sunscreen, hat  and shirt,  light skined individuals  will still absorb  enough rays  on  our hands and legs to  produce  vitamin  D. Since it can be difficult to  get adequate vitamin D in the diet, milk, butter and flour and ready to eat cereals have been fortified with  this essential vitamin  starting in the 1930’s.

Supplements  Rather than Sun

Current guidelines  from  The Institute of Medicine  of the National Academies  Recommended Dietary  Allowance (RDA)  suggest    600 IU ( International Units)  a day for people from 1-70.  Under one  year, the recommendation is  400 IU and  over  70 its  800 ID daily.   I have found that almost every doctor I see is recommending 2000 IU a day to  have a safety margin. Many multi-vitamin supplements already  contain  the RDA for vitamin D.  If you take individual  vitamins, make sure you include a vitamin  D supplement.   Your teeth, bones and immune system will thank you. And don’t forget that  a good sunscreen is  your skin’s best friend.

3 thoughts on “Can Your Sunscreen Lower Vitamin D?

  1. Vitamin D is also crucial for the absorption of Calcium, but you won’t catch me without sunscreen, hat or sun umbrella. I’ll be taking my Vitamin D supplements!

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