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Saturday, October 30, 2010

Do UV Light Bulbs Produce Vitamin D?

With the winter months now here, I've been receiving an increased number of questions about Vitamin D.  First some background on why you may be deficient in Vitamin D during the winter months.  And then I'll touch specifically upon UV lights and UV light bulbs.

I've covered the positive effects of Vitamin D in previous posts.  In fact, you can look at part 1 of a 3-part series I did earlier.    So I won't be going any deeper in this post.  Suffice to say, Vitamin D has MANY benefits.

So let's start with some basics and get a good foundation.  Vitamin D is called the "sunshine vitamin" because our body turns the suns rays into Vitamin D.  During the summer months, 15-30 minutes of direct sunlight when the sun is at its highest (10:30am - 2:30pm) can result in 15,000-20,000 IU of Vitamin D produced by your body.

Let's dig a little deeper into that.  The sun produces two types of rays:  UVA and UVB.  Now, UVA rays are the type you hear all the negativity about.  They damage the skin and are also responsible for tanning.  Tanning salons will use UVA bulbs in their beds (though some do also use UVB).  However, vitamin D production comes from the UVB rays.  When we are talking about natural sunlight, there is another big difference between UVA and UVB.  Our atmosphere will actually deflect UVB rays.  So, depending upon the season and the time of day, you may not get much, if any, UVB rays for Vitamin D production.

In fact, from mid-October through mid-March, the sun will be at such an angle that all the UVB rays will be deflected and not even reach the surface.  That translates into zero Vitamin D production from sunlight.  To get any production, the UV Index needs to be at 3.0 or above.  You can find the UV Index for your area by looking at the EPA's UV Index website.

An easy way to keep track of this...if you live above 42-degrees latitude, then during the winter months the UV Index will be below 3.0 and you will not be able to absorb any UVB rays for Vitamin D production, due to the angle of the sun.  42-degrees latitude runs from the northern border of California through Chicago, IL, and over to Boston, MA.  So if you live north of these locations, you aren't going to get any Vitamin D from the sun during these months.

If you are in one of these locations, then you may want to consider getting your Vitamin D through other methods, due to the plethora of benefits.  My recommendation would be a pharmaceutical grade supplement, as this is the only way you can be guaranteed of receiving the full amount advertised on the bottle in a bioavailable form.  Meaning, it will absorb into your body.

However, there is another method gaining in popularity.  And that would be UV lights and light bulbs.  Light therapy is especially popular with treating SAD (Seasonal Affective Disorder).  But do these lights actually produce Vitamin D?  Well, it depends.  You now know your body needs UVB rays to produce Vitamin D.  So it simply comes down to that.  If the light you are using will emit UVB rays, then you will be able to use it effectively as an alternate to natural sunlight.  It's that simple.

As I stated above, my personal preference is a pharmaceutical grade Vitamin D supplement.  And this one is top notch.  Not only is it pharmaceutical grade, but it is also NSF certified, so it goes through rigorous 3rd party testing.  Each pill is smaller than a Tic Tac and contains 2000IU of Vitamin D.

Just keep in mind, if you live in the northern hemisphere, and above the 42nd parallel, you're going to go almost half-a-year without sufficient UVB rays to manufacture Vitamin D on your own.

For more information, please feel free to contact me via email, Twitter, Facebook, or join our Facebook Fan Page.  And please feel free to link to my blog or share the information via your favorite social media websites.

To Your Health


  1. Yes, UV bulbs do produce vitamin D. I setup my own UV bulbs, and you can too. details at
    Have read > 4,000 article on vitamin D and posted 2500 items at VitaminDWiki. Quick summary: Sunshine is better than UV which is better than vitamin D. I am taking 10,0000 IU and vitamin D AND have a UV bulb.

  2. Could you please bring a vitamin D for me on Monday?

  3. Thanks for that information. Vitamin D can be absorbed from the sun that is why it's called the "sunshine vitamin".

  4. Yes, very true. A point I have brought up in my other posts on vitamin D. And can also be found in the 3rd paragraph of this post.

  5. Holy crap, the title of this post is a simple Yes or No question, yet the first time 'Yes' appears on this page is in the COMMENTS. The first time 'No' appears is well.. now.. in my comment