Vitamin D: Deficiency vs optimum level

Dr. James Dowd of the Vitamin D Cure posted his insightful comments regarding the Institute of Medicine's inane evaluation of vitamin D.

Dr. Dowd hits a bullseye with this remark:

The IOM is focusing on deficiency when it should be focusing on optimal health values for vitamin D. The scientific community continues to argue about the lower limit of normal when we now have definitive pathologic data showing that an optimal vitamin D level is at or above 30 ng/mL. Moreover, if no credible toxicity has been reported for vitamin D levels below 200 ng/mL, why are we obsessing over whether our vitamin D level should be 20 ng/mL or 30 ng/mL?

Yes, indeed. Have no doubts: Vitamin D deficiency is among the greatest public health problems of our age; correction of vitamin D (using the human form of vitamin D, i.e., D3 or cholecalciferol, not the invertebrate or plant form, D2 or ergocalciferol) is among the most powerful health solutions.

I have seen everything from relief from winter "blues," to reversal of arthritis, to stopping the progression of aortic valve disease, to partial reversal of dementia by achieving 25-hydroxy vitamin D levels of 50 ng/ml or greater. (I aim for 60-70 ng/ml.)

The IOM's definition of vitamin D adequacy rests on what level of 25-hydroxy vitamin D reverses hyperparathyroidism (high PTH levels) and rickets. Surely there is more to health than that.

Dr. Dowd and vocal vitamin D advocate, Dr. John Cannell, continue to champion the vitamin D cause that, like many health issues, conradicts the "wisdom" of official organizations like the IOM.

Comments (20) -

  • Anton

    12/19/2010 2:20:07 AM |

    Thanks for your great blog, and for your interest in Vitamin D.

    Along with doctors Dowd and Cannell, add Dr. Holick as another pioneer in Vitamin D. research.

  • Anonymous

    12/19/2010 4:58:25 AM |

    I bet natural vitamin d is far superior to oral supplementation.  I think vit D absorbtion is optimized by low carb, but you also need some sunlight added into the picture.

  • Dr. William Davis

    12/19/2010 1:59:13 PM |

    Hi, Anon--

    Where I live, it's been around 10 degrees Fahrenheit for about two weeks straight. Probably too cold to lay out in a bathing suit.

    For many of us, supplementation is the only choice.

    Also, don't forget that the majority of people after age 40 have lost much of their ability to activate vit D in the skin.

  • kellgy

    12/19/2010 5:02:25 PM |

    I just added his book to my wish list and it will be my next read. I am beginning to wonder why don't we seek to reach serum vitamin D somewhere between 100-150 range. Has there been any research indicating any response to these levels? Even with all the recent research focusing on vitamin D, it would be nice to understand overall health responses at varying degrees of serum content from deficiency to toxicity. We need a wider perspective to draw from.

    BTW, an update: 110 pounds and counting . . . My BMI is about to fall into the normal range and my health has never been better!

    This is an unusual thought. Sitting in front of a very warm and soothing fire last night, I was wondering how my skin reacts to the radiation, aside from the warmth and relaxation benefits.

  • IggyDalrymple

    12/20/2010 3:07:51 AM |

    My level dropped 20 points when I reduced my intake from 10,000 iu/day to 5,000 /day.  I went back to 10,000 and now I'm at 63 ng/ml.  I'll stick with 10,000 iu unless I exceed 100 ng/ml.

  • Susanne

    12/20/2010 7:06:08 AM |

    I wonder if there is not a missing piece to the puzzle of vitamin D deficiency in relation to adequate iodine levels.  I have appended text from the website Iodine4health.  In it Dr. Vickery noticed a connection between the two:

    ”I have also noted an apparent connection between bringing sufficient iodine to a bromine plugged thyroid, and the vitamin D metabolism of the body. Although I am unaware of the exact mechanism, it seems clear that the calcitonin/parathyroid hormone/Vitamin D/calcium balance in the body changes as people on iodine loading programs often register as vitamin D deficient when they did not previously."

    I believe this to be my case.  I tested my vitamin D levels for years and they were optimal based on Dr. Mercola's recommendations and I supplemented with D in the form of cod liver oil rarely.  Then I started taking iodine and I had such a dramatic improvement in symptoms that I knew I had been iodine deficient perhaps my entire life.  After 2-3 years of iodine supplemention I am going to get my D levels tested soon.

  • Anonymous

    12/20/2010 12:10:49 PM |

    Please write the name of the test you underwent to find iodine deficient?Is it a routine blood test that nay primary care doc can order?Readers please chime in please


  • Pater_Fortunatos

    12/20/2010 1:02:01 PM |

    Published less than a month ago:

    Vitamin D deficiency in rheumatoid arthritis: prevalence, determinants and associations with disease activity and disability

  • Anonymous

    12/20/2010 9:58:20 PM |

    "Probably too cold to lay out in a bathing suit."

    Did you try without?
    OK, couldn't resist.

  • Anonymous

    12/20/2010 10:21:05 PM |

    Just a quick question about D3 supplements. I know that dry tabs aren't ideal because they're hard for the body to absorb but what about capsulated powdered D3?

  • Anonymous

    12/21/2010 1:34:06 AM |

    Have an observation using a vitamin D light that I thought to mention.  I take vitamin D capsules and have been doing so for around 5 years.  This winter I decided that I would also use a vitamin D3 light pretty much each day in addition to taking the capsules.  I bought a light sold on Dr Cannell's sight.  I've noticed that sunlight and the artificial D3 light makes me feel warm through out the day, something D3 isn't able to do for me, at least.  And with this cold fall/winter going on right now, this 10 minutes of sunlight is a big plus!    

    Well, there might be a nice bonus from using the light.  I think I'm growing bigger, in a muscular way.  I do work out at a gym and have done so for over 1 years.  Just began the slow burn process last week.  But this muscle growth seems to have started around the time I made a conscious effort to use the indoor light or obtain some sunlight.  

    Anyway, no way to prove, and could be completely wrong about this.  Just something I've noticed as my shirts have grown tighter over the last couple months.  Weight has gone up also by a few pounds. I'm pleased.

  • Jessica

    12/22/2010 7:29:50 PM |

    SMK- the test for iodine that we order in our clinic (family practice) is an iodine loading 24 hour urine test.

    patients take 50 mg of iodoral then capture their urine for the next 24 hours to see how much is excreted.

    There is a 2 week prep, though, that helps ensure the test is accurate.

    Dr. Brownstein (?) has several books on the topic. I think he recommends the load testing method in his book, "Iodine, why we need it, why we can't live without it."

  • Chris Masterjohn

    12/23/2010 2:10:47 AM |

    I'll be posting my comments on the IOM report soon, although this sucker is 999 pages long and taking me a while to read.  I don't think it is at all true that it focuses on "deficiency" instead of "optimal levels."  I think it is quite clearly and very explicitly focused on optimal levels.  

    The IOM claims to not have found sufficient evidence to conclude that higher levels are optimal.  Now, I do believe that there is good enough evidence to act on the hypothesis that levels should be above 30 ng/mL, and my impression so far is that there is very little data supporting an argument for >50 ng/mL as some suggest.  That said, I won't be convinced that the IOM is *wrong* that definitive evidence for greater than 20 ng/mL is lacking until I finish reading the report and look at some of the primary references.

    I do think it's important, however, to exercise the freedom to act on hypotheses.  If we needed definitive evidence for everyone we do, our familial relations and whole lives would fall apart.  Still, I think the IOM had a responsibility to assess the quality of the evidence and only solidify what is definitive into recommendations, as long as those recommendations don't preclude the freedom to use higher levels.

    In any case, hopefully I can finish this bad boy in the next week and blog about it.


  • Anonymous

    12/24/2010 3:43:54 AM |

    Isn't anyone concerned about all those studies summarized in the IOM report showing increased mortality at the highest D levels? 50 ng/ml is the highest level that I can justify targeting.

  • Lacey

    12/24/2010 3:17:52 PM |

    Off topic, but...I wish Paleo bloggers were better at spotting and stopping spam comments.

    Blogger Brooklyn said...Awesome Blog!!! blah blah blah blah

    Funny, Brooklyn had the exact same words to say over on Stephan Guyanet's blog:

    His wonderful blog that he links back to says, among other things, "In the meantime, they recommend that all people, with or without diabetes, should have a healthy balanced diet, low in fat, salt and sugar with plenty of fruit and vegetables." It's also chock full of plagiarized text.

    Sincere paleo fan or linkspammer?  You be the judge.

  • Travis Culp

    12/25/2010 4:38:25 AM |

    Has anyone tested vitamin D levels in indigenous people? I try to dose about 30 minutes a day of sun during solar noon without a shirt on during the summer and 5000 IU a day for the rest of the year. No idea what my level would be though.

  • Peter

    12/25/2010 12:45:12 PM |

    I'm more concerned about official organizations going beyond the evidence (eat margarine! eat carbs! avoid saturated fat!) than  being over-cautious when there's not a lot of reliable research.

  • Anonymous

    1/4/2011 4:26:38 AM |

    One more comment on my apparently deleted comment - there's a possibiliy I never typed in the word verification code, but I believe I did actually post the comment. Sorry, if I did falsely accuse.

  • Brad Fallon

    3/5/2011 6:08:50 PM |

    Vitamin D Deficiency, what is the best natural source apart from sunshine to help keep the levels up?

  • Anonymous

    3/21/2011 4:15:01 PM |

    I just found my new vitamin store. The prices are the lowest I could find. They gave me a free gift of $5.00 with no minimum purchase and I got free shipping! The code I used at checkout is WIR500. Maybe it will work for you too?