Weight loss and vitamin D

At the start of her program, Penny's 25-hydroxy vitamin D blood level showed the usual deficiency at 22 ng/ml.

She supplemented with 8000 units of vitamin D. Another 25-hydroxy vitamin D blood level several months later showed a level of 67.8 ng/ml, right on target.

But Penny also began our diet, including the elimination of wheat, cornstarch, and sugars, and, over 6 months, lost 34 lbs.

Now a much trimmer 146 lbs (still more to go!), another vitamin D blood level: 111 ng/ml.

Penny's weight loss means that the vitamin D is distributed in a smaller total volume, particularly a lower volume of fat.

This is a common phenomenon with substantial weight loss: lose weight and the need for vitamin D is reduced. The reduction in dose is roughly proportion to the weight lost. Vitamin D should therefore be reassessed with any substantial change in weight of, say, 10 lbs or more, either up or down, because of the influence of fat on vitamin D blood levels.

Some references on this effect:

Men and women over age 65:
Adiposity in relation to vitamin D status and parathyroid hormone levels: a population-based study in older men and women.

Obese women:
Low 25-hydroxyvitamin D concentrations in obese women: their clinical significance and relationship with anthropometric and body composition variables

Obese children:
Hypovitaminosis D in obese children and adolescents: relationship with adiposity, insulin sensitivity, ethnicity, and season.

Relationship of vitamin D and parathyroid hormone to obesity and body composition in African Americans.

Although the bulk of the effect is most likely due to sequestration by fatty tissue, perhaps less sun exposure in obese people also contributes:
Body mass index determines sunbathing habits: implications on vitamin D levels.

Comments (28) -

  • Sabio Lantz

    8/29/2009 10:26:57 AM |

    May I ask, what is the optimal serum range for Vit D.  What do you consider too high and what are the undesirable consequences of too much vitamin D?
    Thank you kindly -- fantastic blog !

  • David

    8/29/2009 1:43:39 PM |

    I wonder- do you have a general rule of thumb for a starting dose based on how much the person weighs? I've found that 1,000 IU per 25 lbs of bodyweight seems to generally get it in the ballpark.

  • Dr. William Davis

    8/29/2009 1:51:01 PM |

    The "1000 units per 25 lbs body weight" that Dr. John Cannell suggests does indeed work well, though there is still great variation among individuals.

    For that reason, we aim to maintain blood levels of 25-hydroxy vitamin D of 60-70 ng/ml.

  • steve

    8/29/2009 2:07:28 PM |

    can supplementing with D3 negatively impact TSH thyroid levels, causing TSH to increase? I have seen this stated on another blog.  Suggested remedy was to lower intake of D3.  Thanks.

  • J. Weight

    8/30/2009 3:41:53 AM |

    With daily effort your endurance will continue to increase. In no time at all you will be able to sustain 30 minutes of continued activity. Now as you begin to get into better shape you will be on your way to experiencing fast weight loss.

  • barry

    8/30/2009 12:48:18 PM |

    Great article, I'd never known how vitamin D was related to weight loss until now.

    But, with all supplements for weight loss it would need to be combined with exercise for best results

  • Kate

    8/31/2009 1:17:05 AM |

    I have the same question as Steve: Can increased D3 affect TSH or thyroid in general. I have hashimotos thyroid autoimmune, and have increased my D3 for osteoporosis reasons, but it seems to be affecting my TSH---need less medication to have same levels of normal TSH.  I read that D is good for autoimmune disease.
    Thanks for your response!

  • sleeve gastrectomy

    8/31/2009 11:07:20 AM |

    Awesome! really very nice article.

  • dotslady

    8/31/2009 5:02:02 PM |

    I wanted to take more than 4,000iu because I'm obese (11-17-08 level was 64, 8-3-09 level is 55), but my PCP said not to for fear of kidney problems?  I just upped it to 8,000iu.  We'll see - I sure could use help in the weight loss arena.

  • Ask A Doctor

    9/1/2009 10:22:19 AM |

    Though the levels of vitamin d and weight loss seem to be correlated, is it always true.

  • Helena

    9/2/2009 5:04:26 PM |

    Dr. Davis
    (Probably not the right forum to post this comment but I just had to send this to you)

    Not many weeks ago a colleague of mine (let’s call him Eric) asked me if I knew the difference between D2 and D3 and I told Eric that D2 comes from irradiated mushrooms and D3 comes from the wool. In other words D3 is the same kind of vitamin as humans get from the sun. Humans just don’t get enough and we can’t produce it on our own, like the sheep can. (D3 is natural for humans, D2 is not just like you have said)

    After telling Eric this, he asked me how he would know what he is taking and I gave him the medical definitions of them both (D2 = Ergocalciferol; D3 = Cholecaliciferol). Since I was aware of that he had gotten his Vitamin D by prescription I told him “I am 99.9% sure that you are taking D2, but I would be thrilled to find out I am wrong”.

    Eric called his pharmacy right away and got the answer I was expecting: Ergocalciferol. When confronting the person Eric was talking to the answer he got back was that Ergocalciferol is the only Vitamin D they are giving out.

    A week later, Eric had a new appointment with his doctor and decided to ask him about the D2/D3 issue. The doctor said he knew that there was a difference in them both, but could not say what, not even the basic facts I mentioned above. But the doctor stamped a post-it with what he had sent to the pharmacy just to show Eric… “Vitamin D3; 50,000IU tab” is what the stamp said.

    Eric, off course, got confused and was starting to believe that the Pharmacy had made a mistake by giving him Ergocalciferol (D2) since the doctor had given him D3, or at least that is what was stamped on the little note he had.

    Today, after getting a refill of his Vitamin D he also got and kept all his paperwork that came along with it. Still in believe about that stamp the doctor had given Eric earlier he asked me to double and triple check that my definition of D2 and D3 was correct. I did, just for my own sanity, and I was still right.

    One of the sheets Eric brought me today was the “Patient Education Monograph” sheet stating the drugs and how to use it and so on… The thing the jumped out the most to me was this:

    Generic Name: Vitamin D – Oral
    Common Brand name(s): Drisdol, Maximum D3
    Identification: PA140 Green Oval Capsule

    This is the Drug Eric was given: Vitamin D 1.25 MG softgel; Generic name: Ergocalciferol

    My researching mind went into high concentration mood and I started to dig. And this is what I found:

    The brand name Drisdol is Ergocalciferol (D2), not D3. The Brand name Maximum D3 seems to be hard to find out there in cyber space as a brand name. But the ones I found that was called Maximum D3 seems to be the real stuff, however none of them required a prescription.

    When trying to find out through the identification number on the pills (PA140) I now know for sure that Eric is taking Vitamin D2 and not the preferably Vitamin D3. The Brand Name Drisdol had the identification W on one side and D92 on the other, but it is still Ergocalciferol.

    The only conclusion I can draw from all this is that the medical industry does not know or care about the difference in D2 and D3 – it is all same to them. And as long as the pharmacies only give out D2 it does not matter what the doctor prescribe anyway.

    I knew that people are most likely to be prescribed a D2 pill than to be told to buy over the counter D3. But it was almost heart breaking to see the letter D and number 3 right next to the drug Drisdol as we know is a D2 vitamin. It just didn’t make sense to me that they can be labeled as the same type of medication, when we know it is not!

    I love your blog, and I just wanted you to know that I am passing on your information to as many as I can. If you are interesten in seeing any of the documents that I have from this story you can just email me at helena.mathis@hotmail.com

  • Anonymous

    9/3/2009 11:48:10 AM |


    shouldn't you take helena mathis' email off the blog post ?

  • Plamen Ivanov

    9/8/2009 12:40:29 PM |

    This looks interesting.

  • trinkwasser

    9/10/2009 3:36:27 PM |

    Good point! I suppose this is true of anything fat-soluble, if you reduce the fat deposit then the concentration will increase?

  • Health Vitamins

    10/2/2009 6:03:05 AM |

    wow..excelent post, thanks for sharing

  • mirandasierra

    11/10/2009 11:09:28 AM |

    thanks for this - with all sorts of info available on the net - this one gives me a greater understanding on vitamin D in relation to my weight loss level. More posts like this Smile

  • TheS0urce

    11/28/2009 8:23:56 AM |

    I take calcium with my vitmain D3.  The vitmain D3 I take has olive oil with it.  It is highly advised to take calcium when taking more than 1000 UI daily.  You should get tested for vitamin D3 levels in your blood.  You can get a private lab or do it through a doctor.  I take 1000 UI for every 25 lbs.  I tried taking it a few days that way and I lost 4 lbs in a few days.
    You shouldn't take more the recommend amount on the bottle more than a few months.

  • Canadian pharmacies online

    12/9/2009 10:52:16 AM |

    Thanks Every body for sharing information ....Smile

  • John

    12/17/2009 12:52:35 AM |

    You really need to consult a doctor if you have any plans to lose weight. Ask for a prescription of the right dosage of Vitamin D and eat nutritious foods as well. Don't forget to exercise too, its helpful.

  • F. Belt

    5/31/2010 2:47:07 PM |

    In my case, I created my own – FatBlasters. It’s essential that you not feel alone, and reaching out to friends (new or old) is typically a smart move. I just heard about PeetTrainer, but didn’t know about it when I began down the road to weight loss. You have to know that others are out there for moral support – they know things that you couldn’t possibly know, and they’ve probably been “in your shoes” at some point in the past (or present). Share stories, laughter, tears, successes, and failures – share them. There are thousands of communities out there, so keep looking until you find the one that fits you.

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    9/29/2010 5:24:45 AM |

    Nice post on the Vitamin D and weight loss. Overweight is one of the major problem in the world. People do lot of things for losing the weight.

  • weight loss

    10/4/2010 11:15:51 AM |

    What is suggested here is that if you start out with an inadequate vitamin D level, it’s possible that this might inhibit or impede your ability to lose weight on a reduced caloric diet?

  • Aiden

    10/27/2010 8:33:33 AM |

    yes my dear friend ,definitely you lose weight on a reduced caloric diet, HCG diet , thanks

  • sherin

    10/28/2010 5:50:19 AM |

    There is many more information on this post about how to reduce our weight loss and also there is plenty of information about the functions of vitamin D in weight loss.Office plugin Its really a helpful information to all of us.

  • buy jeans

    11/3/2010 7:35:16 PM |

    This is a common phenomenon with substantial weight loss: lose weight and the need for vitamin D is reduced. The reduction in dose is roughly proportion to the weight lost. Vitamin D should therefore be reassessed with any substantial change in weight of, say, 10 lbs or more, either up or down, because of the influence of fat on vitamin D blood levels.

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    11/12/2010 4:03:06 PM |

    Vitamin D is good for weight loss.

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