Vitamin D on Good Morning America


Positive comments about vitamin D made it to a discussion on Good Morning America today about the new and exciting developments in nutrition and "functional foods".

I'm thrilled that the media is conducting these conversations. It sure is making my job easier, not having to persuade patients that taking vitamin D is truly and hugely beneficial for health. I still have to struggle with my colleagues, who tell patients to stop the "poisonous" doses we use.

But I worry that many of the details behind vitamin D don't quite make it to the media conversation. These are crucial, make-it-or-break-it issues, such as:

--Vitamin D must be vitamin D3 or cholecalciferol, not D2 or ergocalciferol. D2 is virtually worthless. Little or none is converted to the active D3, despite the fact that D2 is the form often added to some foods.

--Vitamin D3 supplements must be oil-based capsules, or gelcaps. Tablets are so poorly or erratically absorbed that it's simply not worth the effort. (We get ours from the Vitamin Shoppe.)

--The dose should be sufficient to eliminate the phenemena of deficiency, which is around 50 ng/ml. I take 6000 units per day. Dr. John Cannell of www.vitamindcouncil.com takes 5000 units per day. I give my wife 2000 units per day (she's not as deficient as I was), each of my kids 1000 units per day, except for my 180 lb. 15 year old who takes 2000 units.

I fear that, when people hear that vitamin D packs fabulous effects for health, they will take a 400 unit tablet--nothing will happen. They will not obtain the benefits such as reduction of blood pressure and blood sugar; increased bone density, reduction of arthritis, dramatic reduction in risk for fractures; reduction in risk for colon, prostate, and breast cancer; reduction in risk for multiple sclerosis; reduction in inflammatory processes such as those evidenced by C-reactive protein; and facilitation of reduction of heart scan score.

Comments (9) -

  • Meredith Curry

    2/1/2007 1:24:00 AM |

    Ooh, that's interesting about D3.  Glad you explained that.  I'm going to check it out right now.  Thanks doc Smile

  • Cindy

    2/2/2007 2:04:00 AM |

    A few months back I read that D2 was what was used in fortifying milk and other foods. Do you know if that's changed?

    Curious what you would recommend for a woman with no known D deficiency? Or should we all get levels done? I have a rather uncooperative doc and it's just not worth trying to get her to order blood work, and I can't afford to get it done without insurance coverage. I currently take 1000iu pills (in oil) 2 one day and 3 the next.

  • Dr. Davis

    2/2/2007 3:06:00 AM |

    Unfortunately, nothing substitutes for a blood level of 25-OH-vitamin D3.

    However, common factors that affect your vitamin D3 requirement include:

    --Body size
    --Skin color--the more dark-skinned you are, the greater your requirement.
    --Sex--Males require more, females less.
    --Geographic location--Extremely important. Northern climate requirements are probably about half that of southern climates in winter.

    If you are unable to obtain a blood level and you are not exposed to substantial sun, then 2000 units per day of an oil-based gelcap would be a reasonable quantity. But please keep in mind that this is an estimate, not a precise prescription.

  • Jim

    2/3/2007 7:07:00 AM |

    The media and many experts either ignore or minimize the fact that all the vitamin D3 a human body can use is processed naturally during just one or two sessions a week in a tanning bed.  

    The UVB from tanning bed lamps is more effective processing vitamin D3 that the Sun in Northern states during the Winter.  

    Moderation is the key. Don't sunburn.  

    One can feel good about looking good and healthy with a tan.

  • David

    2/5/2007 9:53:00 PM |

    Is cod liver oil a good source for vitamin D3 & if so, what dosage? Does the presence of vitamin A complicate things (ie toxicity). TIA

  • Dr. Davis

    2/7/2007 6:15:00 AM |

    Cod liver oil would not be my first choice. Problems: great variation in vitamin D content, saturated fat, and vitamin A.

    In my view, the best way to get vitamin D (when sun is not available) is a vitamin D--only-- supplement. That way you can regulate the amount you need with reasonable precision.

  • David

    2/7/2007 9:01:00 PM |

    Thx for your reply. Saturated fat in cod liver oil? Hmmm ... that's a surprise. I had the impression that it was loaded with omega-3 fats. Hell, what do I know?

  • buy jeans

    11/3/2010 10:17:11 PM |

    They will not obtain the benefits such as reduction of blood pressure and blood sugar; increased bone density, reduction of arthritis, dramatic reduction in risk for fractures; reduction in risk for colon, prostate, and breast cancer; reduction in risk for multiple sclerosis; reduction in inflammatory processes such as those evidenced by C-reactive protein; and facilitation of reduction of heart scan score.

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Vitamin D for Peter, Paul, and Mary

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:  http://sparkasynapse.blogspot.com/2009/03/vitamin-d-results.html

    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:
    http://www.cholesterol-and-health.com/Vitamin-D.html

  • Peter Silverman

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

    Article in yesterday NY Times regarding high doses of D3 protecting against fractures:
    http://www.nytimes.com/2009/03/31/health/research/31aging.html?ref=health
    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: http://dailyviews.runnersworld.com/2009/03/i-will-never-ev.html

  • 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 |

    Ricardo

    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?

    thanks,
    nancy

  • Anonymous

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

    Can someone list the effects of overdosing on D3?

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