How to Avoid D-ficiency.

D-fining the needs.  

Over the last few years Vitamin D has been touted as the wonder vitamin, but there is a lot of conflicting information, guidelines are continually changing and much of the population suffers from Vitamin D insufficiency. It's important to clarify the guidelines and our needs, because unlike other vitamins and minerals, it can be difficult to get enough Vitamin D from food.  In fact, it's not a vitamin at all, but rather a hormone produced by the body with UV exposure from sunlight on the skin. (Note: there are some foods, such as soy milk and orange juice, that are fortified with D, but it's generally not enough for your daily needs). 

But is insufficient Vitamin D deadly?

While there is a lot of confusion surrounding Vitamin D, the claims about the benefits of adequate levels live up to the hype.  Vitamin D plays a role in:

  • fertility and reproduction
  • growth and development
  • bone health
  • regulation of calcium, magnesium and phosphorus levels in the blood
  • immune and stress response
  • digestive system function
  • endocrine regulation 
  • central nervous system (brain) function

Adequate levels of Vitamin D can reduce risk of falls, fractures, respiratory tract infections and ALL-CAUSE mortality.  That's right- Vitamin D essentially can help you live longer by protecting you from death by ANY cause.  There have been 56 randomized control trials consisting of a total of 95, 286 participants (that's a lot!) that showed Vitamin D decreased mortality (death) by up to 11%.  This only applied to Vitamin D3 (cholecalciferol- the type derived from plants and animals) and NOT Vitamin D2 (ergocalciferol- the type derived from fungus).

Soaking up a few minutes of Vitamin D in Cascais, Portugal before applying my non-toxic sunscreen.  Photo by: Emma Kate

Soaking up a few minutes of Vitamin D in Cascais, Portugal before applying my non-toxic sunscreen.  Photo by: Emma Kate

Sun or Supplements?

Biologically we are meant to be exposed to far more Vitamin D from the sun, but because our modesty got the best of us and we aren't all running around naked anymore in equatorial Africa, we're lucky if 5% of our skin is left unsheilded from the sun.  Even if we did spend a few hours a day lounging naked in the sun, the depletion of the ozone layer has increased the risk of skin cancer.  Sun rays, like processed meat, are considered a class 1 carcinogen (that equals high cancer causing potential).  The threat for cancer, however, is most commonly from excessive and chronic sun exposure and burns.  

Sunscreen blocks the absorption of Vitamin D, so slathering on sunscreen and exposing your skin gets you nowhere.  It's generally okay to go outside for 10-15 minutes in the late morning hours before applying sun protection to absorb a little D, but most of us don't live close enough to the equator to fulfill our needs throughout the year (hello, New England winter).  

And so, many healthcare professionals ARE recommending regular Vitamin D3 supplementation. The Vitamin D blood level sweet spot is 75-80 nmol/l.  The problem is there is A LOT of variation among lab assays, so blood testing isn't all that helpful.  In fact, most organizations are now recommending against having blood levels checked routinely.  Instead, a safe dose that would get 80% of the U.S. population in a healthy range would be 2,000 international units (IU) of Vitamin D3 daily.   

Taking a Vitamin D supplement does not give you license to down doughnuts everyday!  The health benefits are an adjunct to an otherwise healthy lifestyle.  As always, you should run any new medication or supplement by your healthcare provider.

For more information about your Vitamin D needs see and for a helpful resource to determine the best AND most affordable brands check out this super helpful resource from