Last month, I was catching up on the doctors' visits and routine blood work.  While at the neurologist's office, I picked up an order for the appropriate laboratory tests which would satisfy the needs of all three of my doctors (neurologist, rheumatologist, internist), including a test to measure vitamin D levels.  

One blood draw + One laboratory report 

     = Three satisfied doctors + One happy patient

When requesting to have your vitamin D levels checked, it is important to ask for the 25(OH)D(3) or 25-hydroxyvitamin D test which is necessary to detect true deficiency.

In September 2008, I measured severely deficient in vitamin D at 7.8 ng/mL.  Since then, we have been randomly checking the progress on my attempt to increase those levels.  So far the highest I have obtained is 44 ng/mL. 

Vitamin D Deficiency

As you begin to read the vast amount of research conducted on vitamin D and its effect on various diseases, you will soon see that finding a recommendation for optimum serum levels can be difficult.  For one thing, the recommendations have changed dramatically over time.  For another, there are two different measuring systems referenced in the literature.

nanograms per millilitre (ng/mL) or nanomoles per litre (nmol/L)

For simplicity, here is a chart which summarizes the current recommendations:

25(OH)D Levels and Health Implications

You can see how my measly 7.8 ng/mL is nonexistent.  Last month's results came back at 36 ng/mL.  Good, right?  36 ng/mL measures "sufficiency."  Well, not really.

My neurologist would prefer to see vitamin D levels above 50 ng/mL (>125 nmol/L) and gave me a new prescription for vitamin D2 (50,000 UL of ergocalciferol), something I had taken previously.  In contrast, my internist was satisfied with 36 ng/mL.  When I asked my rheumatologist what level she prefers, she responded that between 50-80 ng/mL would be safe, then she gave me a back-up prescription for when the other one ran out.

Two out of three of my personal physicians recommend a higher level of serum vitamin D than the limits of the "normal range" which my laboratory uses.  The Vitamin D Council recommends that serum levels of vitamin D should be at least 50 ng/mL in healthy individuals.  However, this doesn't mean that YOUR doctors would recommend 50-80 ng/mL for YOU.

How much Vitamin D should I take?

The type of vitamin D which is formed when sunlight containing ultraviolet light (UVB) hits bare skin is called cholecalciferol.  Enormous quantities of cholecalciferol, on average 20,000 units, is rapidly made in the skin if: 

• the sun is high in the sky which occurs at midday (10 AM-3 PM), in the summer months, and at higher altitudes

• your skin is not covered by clothes or sunblock (exposing the face and hands is not enough)

• you stay in the sun until your skin just begins to turn pink, not red (which takes longer for individuals who have more skin pigmentation)

• you are not behind glass (as glass blocks UVB, preventing vitamin D from being made)

Over the counter vitamin D supplements provide cholecalciferol, also referred to as vitamin D3.  These tablets are available in doses anywhere from 100 IU to 5000 IU, or even 10,000 IU.  Although I had been taking daily doses of 5000 IU vitamin D3 for several months, my serum levels were still too low at the end of this winter.