Vitamin D for Peter, Paul, and Mary

Why is it that vitamin D deficiency can manifest in so many different ways in different people? One big reason is something called vitamin D receptor (VDR) genotypes, the variation in the receptor for vitamin D.

It means that vitamin D deficiency sustained over many years in:

Peter yields prostate cancer

Paul yields coronary heart disease and diabetes

Mary yields osteoporosis and knee arthritis.

Same deficiency, different diseases.

VDR genotype-determined susceptibility to numerous conditions have been identified, including Graves' thyroiditis, osteoporosis and related bone demineralization diseases, prostate cancer (Fok1 ffI genotype), ovarian cancer, rheumatoid arthritis, breast cancer (Fok1 ff), birth weight of newborns, melanoma and non-melanoma skin cancers, insulin resistance and metabolic syndrome, susceptibility to type I diabetes, Crohn's disease, and neurological or musculoskeletal deterioration with aging that leads to falls, respiratory infections, kidney cancer, even periodontal disease.

Why is it that the dose of vitamin D necessary to reach a specific level differs so widely from one person to the next? VDR genotype, again. Variation in blood levels of 25-hydroxy vitamin D from a specific dose of vitamin D can vary three-fold, as shown by a University of Toronto study. In other words, a dose of 4000 units per day may yield a 25-hydroxy vitamin D blood level of 30 ng/ml in Mary, 60 ng/ml in Paul, and 90 ng/ml in Pete--same dose, different blood levels.

Should we all run out and get our VDR genotypes assessed? So far the data have not progressed far enough to tell us. If, for instance, you prove to have the high-risk Fok1 ff genotype, would you do anything different? Would vitamin D supplementation be conducted any differently? I don't believe so.

Virtually all of us should be supplementing vitamin D at a dose that generates healthy blood levels, regardless of VDR genotype. For those of us following the Track Your Plaque program for coronary plaque control and reversal, that means maintaining serum 25-hydroxy vitamin D levels between 60-70 ng/ml.

As the fascinating research behind VDR genotype susceptibility to disease unfolds, perhaps it will suggest that specific genotypes be somehow managed differently. Until then, take your vitamin D.

Comments (15) -

  • Kiwi

    3/27/2009 8:48:00 PM |

    I've been taking vitamin D for about five months now after reading Dr. Davis' excellent blog.
    Was taking two Thompson's D 1000 caps/day. Latest test result for 25 hydroxy came back at 142 nmol/l so have cut back to one cap/day. So yes, dose depends on body type and sun level (summer here).

  • Kiwi

    3/27/2009 9:00:00 PM |

    I've just done the conversion to ng/mL. Is that by dividing by 2.5? Perhaps I should keep up the two caps/day?

  • Dr. William Davis

    3/27/2009 10:39:00 PM |

    Yes. 142 nmol/L = 56.8 mg/dl.

  • Monica

    3/28/2009 1:41:00 AM |

    Thanks for blogging on this, Dr. Davis.  I just got my test for the first time and was alarmed that I came in at only 30 ng/mL after supplementing with 1000 IU daily for about a year.  I had previously lived in Syracuse, NY, the cloudiest city just behind Seattle.  And on a grain-based crap diet, too.  No longer.  Here's my vitamin D story:

    I've been wheat-free for 9 months now, but this makes me really curious about my lipid profile...  I still have a ways to go to reach optimum health.  I'm only 34 so hopefully plenty of time to correct this problem.  Unfortunately for my older relatives they were not so lucky.  Cancers, diabetes, heart disease abound.

  • Anonymous

    3/28/2009 5:58:00 AM |

    Have you any comment on this:

  • Peter Silverman

    3/28/2009 10:28:00 AM |

    Article in yesterday NY Times regarding high doses of D3 protecting against fractures:
    Unfortunate that the title says pills not capsules.

  • Anonymous

    3/28/2009 5:17:00 PM |

    I was also very shocked with my vitamin d test results. After 5 months @ 6000iu daily my level was only 34 ng/mL. It is winter but I work outside and seldom use suncreen.

  • Anonymous

    3/28/2009 9:34:00 PM |

    The Toronto study suggests there are polymorphisms of the D-binding protein. Isn't this a separate entity than VDR, which is present on cellular surface in many tissues? Maybe I am misunderstanding something ....Thomas

  • Ricardo

    3/28/2009 10:46:00 PM |

    Dr. Davis, should runner's use some suncreen? I was reading this article and decided to ask here:

  • Kismet

    3/29/2009 11:12:00 AM |

    As the evidence currently stands everyone should wear sunscreen *and* supplement vitamin D. (benefits of red & blue light can be had without dangerous UVR)

  • rabagley

    3/29/2009 9:56:00 PM |

    Basically, we should all be getting full-spectrum sunlight in moderate amounts.  Moderate means that you have browning or slight reddening of the skin (if you're still red the next day, that was too much).  This does increase your risk of carcinomas (a low risk type of cancer), but minimizes your risk of melanomas (an extraordinarily high risk type of cancer).  Repeated sunburns increases your risk of melanoma and should be avoided if at all possible.

    As a runner, it's often difficult to control the length of time you spend in the sun to moderate your exposure.  The length of time you spend running will usually have more to do with your exercise goals than your sun-exposure goals.  This means that you will most likely not be able to maintain moderation and would put yourself at increased risk of dangerous cancers.

    So starting from a completely different set of assumptions, I reach the same conclusion as Kismet, that you should probably be wearing sunscreen and supplementing with Vitamin D3 gelcaps.

  • TedHutchinson

    3/30/2009 11:22:00 AM |


    Skin Cancer/Sunscreen - the Dilemma

    and everyone else will benefit from  watching the Edward Gorham's video or if time is short at least look at the slides used in his presentation
    Skin Cancer/Sunscreen -- the Dilemma slides PDF
    No one should ever allow skin to burn. Prolonged UVB exposure   processes any vitamin d near the skin surface into suprasterols that are not usable, so alternating short sun sessions with time for the skin to cool down and Vitamin D to be absorbed will optimize the process.

  • Rick

    4/2/2009 7:11:00 AM |

    This lecture is entertaining and informative:
    Vitamin D

  • Anonymous

    4/6/2009 10:34:00 PM |

    I have always purchased Vitamin D3 from fish oil but discovered while shopping this weekend that there is also a Vitamin D3 obtained from 'wool' or 'lanolin'.  I had never seen this before.  Which is preferable? from fish oil or from lanolin?


  • Anonymous

    4/10/2009 6:24:00 PM |

    Can someone list the effects of overdosing on D3?