# I Have Vitamin D Deficiency?! **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 24, 2013, 8:52am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097 "2013-10-24T08:52:55Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [October 24, 2013, 4:53pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/21 "2013-10-24T16:53:50Z")
Interesting. I was told at my last checkup that I have vitamin D deficiency, too. I never use sunscreen (me bad) and I live in Texas, where there’s plenty of sun and I am often out in it. I walk my dogs twice a day. Sometimes I wonder if some Blood Test Regulation Conspiracy in the Sky doesn’t go in and change “normal” values in order to drive sales of supplements, etc. Nah. Nothing like that could be going on. > [@brazil84](#): > > I’m not an expert but I recall reading that Vitamin D is absorbed best by the body if consumed with fat. So… this means I can wrap my vitamin D pill in bacon? All-RIGHT!! ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [October 24, 2013, 5:24pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/22 "2013-10-24T17:24:26Z")
> [@ThelmaLou](#): > > Sometimes I wonder if some Blood Test Regulation Conspiracy in the Sky doesn’t go in and change “normal” values in order to drive sales of supplements, etc. Nah. Nothing like that could be going on. My suspicion is that in the past, they pretty much set the RDA for vitamin D, and if you didn’t have some gross manifestation of deficiency, it was neither tested for or worried about. Nowadays, I suspect the blood test is much cheaper and is probably done as part of regular care, and doctors are finding that people are much more deficient than they realized. It’s almost certainly due to some sort of measurement advance, not some other problem with nutrition; I’m sure everyone in the 20th century was just as deficient as today, but nobody knew. ---
**Author:** ![James\_Toothpaste](https://avatars.discourse-cdn.com/v4/letter/j/e56c9b/32.png) [@James\_Toothpaste](https://boards.straightdope.com/u/James_Toothpaste)\ **Post date:** [October 24, 2013, 6:59pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/23 "2013-10-24T18:59:21Z")
It seems like a lot of people have vitamin D deficiency. I have noticed it is one of the hardest vitamins to get. ---
**Author:** ![mandala](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mandala/32/95_2.png) [@mandala](https://boards.straightdope.com/u/mandala)\ **Post date:** [October 24, 2013, 7:27pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/24 "2013-10-24T19:27:34Z")
Is Vitamin D deficiency linked to depression at all? I have heard both ways. But a doctor told me the myth persists because people with Seasonal Affective Disorder (SAD) show real clinical depression, this peaks during the winter months, and just happens to coincide with the time people also get the lowest sun exposure and consequently have lower D levels in blood. In any case, taking 5000 IU of vitamin D every day has done me no tangible good at any level. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [October 25, 2013, 1:18am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/25 "2013-10-25T01:18:27Z")
> [@Superhal](#): > > Sunlight. > > 10 chars. Is “getting more sunlight” a meaningful treatment for most Vitamin D deficiencies, or are we talking about problems with the body just not using the sunlight it’s getting? 19th century novels are replete with protagonists who are advised by their doctors to move to a different climate - is this a case where “Take a trip someplace sunny - I don’t know, Hawaii maybe, or the South Pacific, or the Caribbean, or Key West, or Egypt maybe, but stay the hell away from Anchorage for a bit.” could really help? ---
**Author:** ![jabiru](https://avatars.discourse-cdn.com/v4/letter/j/bbce88/32.png) [@jabiru](https://boards.straightdope.com/u/jabiru)\ **Post date:** [October 25, 2013, 1:29am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/26 "2013-10-25T01:29:13Z")
Everyone I know has had their Vitamin D levels come back low. I was surprised to discover that I Don’t Have a Vitamin D Deficiency! ---
**Author:** ![Lightlystarched](https://avatars.discourse-cdn.com/v4/letter/l/eb8c5e/32.png) [@Lightlystarched](https://boards.straightdope.com/u/Lightlystarched)\ **Post date:** [October 25, 2013, 3:59am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/27 "2013-10-25T03:59:46Z")
I thought I read somewhere that bathing after sun exposure will wash away the vitamin-producing oils from the surface of your skin before they’ve had a chance to penetrate into the bloodstream. Maybe we’re all just too clean to get enough Vit D? ---
**Author:** ![China\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/779978/32.png) [@China\_Guy](https://boards.straightdope.com/u/China_Guy)\ **Post date:** [October 25, 2013, 4:43am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/28 "2013-10-25T04:43:10Z")
Every time I visit a doctor here in Seattle the question is asked are you taking vitamin D supplements? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 25, 2013, 5:20am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/29 "2013-10-25T05:20:22Z")
> [@Broomstick](#): > > Yes, there is a normal range. > > There are several factors involved in the sudden “epidemic” of Vitamin D deficiency. > > 1. … And the normal range was recently raised. Used to be 20 and below was “low”; now 30 and below is reported out as “low.” What is actually ideal is unclear. Your otherwise excellent list also neglects to include the impact of obesity on Vitamin D levels. [Here’s](http://jcem.endojournals.org/content/96/7/1911.full) one authoritative summary: > [@](#): > > The major source of vitamin D for children and adults is exposure to natural sunlight (3, 7, 35,–,37). Very few foods naturally contain or are fortified with vitamin D. Thus, the major cause of vitamin D deficiency is inadequate exposure to sunlight (5,–,7, 38). Wearing a sunscreen with a sun protection factor of 30 reduces vitamin D synthesis in the skin by more than 95% (39). People with a naturally dark skin tone have natural sun protection and require at least three to five times longer exposure to make the same amount of vitamin D as a person with a white skin tone (40, 41). There is an inverse association of serum 25(OH)D and body mass index (BMI) greater than 30 kg/m2, and thus, obesity is associated with vitamin D deficiency (42). [Here’s](http://jcem.endojournals.org/content/97/4/1153.full) another that summarizes some of the debate over what “normal” should be. It really is not clear and likely in truth varies between individuals based on other factors that we do not yet quite get. (For example Black Americans have lower Vitamin D levels but _less_ osteoporosis.) [One more](http://www.eje-online.org/content/169/4/R59.full) review: > [@](#): > > The definition of vitamin D deficiency, insufficiency, and sufficiency is currently challenging as an overall consensus is still lacking (48, 49, 50). It represents a crucial issue, as the identification of different thresholds defining vitamin D status has varying implications in clinical practice. First, the worldwide prevalence of low vitamin D status is highly varying according to the level of 25(OH)D utilized to define sufficiency. Consequently, the choice to initiate vitamin D supplementation may change, as well as the goals of therapy, the dosing strategy, and the decision about who should be screened, if necessary, and how often (51). > > In recent years, a number of position statements and clinical practice guidelines have been published to define the optimal vitamin D status and the health outcomes associated with its alteration (52, 53). Many different recommendations on dietary intakes needed to reach and maintain sufficient 25(OH)D levels have been proposed as well (54, 55, 56, 57, 58, 59). > > In this context, the publication of the two most authoritative reports on these issues (one released from the Institute of Medicine (IOM) committee’s 2011 report on dietary reference intakes for calcium and vitamin D and the other from the Endocrine Society clinical practice guideline for the evaluation, treatment, and prevention of vitamin D deficiency) (58, 59) has lead to confusion among clinicians, researchers, and the public because of the disagreement in data interpretation. The conclusions of the two reports indeed differ considerably. The US Endocrine Society (ES) reported a 25(OH)D level \<20 ng/ml (50 nmol/l) as the ‘cut off’ to define vitamin D deficiency, a 25(OH)D level between 21 and 29 ng/ml (52.5 and 72.5 nmol/l) to define vitamin D insufficiency, and a 25(OH)D level more than 30 ng/ml (75 nmol/l) as the optimal level. In contrast, the IOM concluded that 25(OH)D levels above 20 ng/ml are needed for good bone health for almost all the individuals (97.5% of the population), while a level of 16 ng/ml (40 nmol/l) meets the need of approximately half the population. According to the IOM, higher levels of 25(OH)D have not been consistently shown to confer greater benefits, in turn challenging the concept that ‘more is better’. … **Lightlystarched** - not true. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [October 25, 2013, 11:02am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/30 "2013-10-25T11:02:17Z")
> [@Lightlystarched](#): > > I thought I read somewhere that bathing after sun exposure will wash away the vitamin-producing oils from the surface of your skin before they’ve had a chance to penetrate into the bloodstream. Maybe we’re all just too clean to get enough Vit D? Vitimin D production has nothing to do with surface oils in humans. It requires penetration of the skin by UV (which happens if you don’t use sunblock). Wash all you want after sun exposure, it makes no difference to D production. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [October 25, 2013, 2:13pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/31 "2013-10-25T14:13:24Z")
> [@Broomstick](#): > > Vitimin D production has nothing to do with surface oils in humans. It requires penetration of the skin by UV (which happens if you don’t use sunblock). Wash all you want after sun exposure, it makes no difference to D production. Some vitamin D precursors are made on the surface of this skin. It seems reasonable to expect that these washing could remove these. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [October 25, 2013, 3:31pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/32 "2013-10-25T15:31:22Z")
> **[Vitamin D Council (VDC) | Profile](https://yippy.health/yp/vitamin-d-council)** > > at yippy: The importance of vitamin D and its effect on various diseases. Get reliable information from the Vitamin D Council and yippy HEALTH. > [@](#): > > Dr. Cannell: Does showering after sunbathing wash off the Vitamin D? Sarah, Oklahoma > > Yes, but how much of the skin’s total production? Agnes Helmer and Cornelius Jensen published a remarkable human/animal study in 1937, showing that significant amounts of Vitamin D are made on the surface of human skin. Reverend Jensen, the senior author, was a professor of biophysics as St. Thomas Aquinas, the precursor of the University of Dayton. **The authors collected surface oils from young men before showering, irradiated the oils, and showed those oils contained large amounts of Vitamin D, enough to cure rickets in animals. Then, they tested a very practical question; can those oils be removed by washing? Indeed they found washing, even with plain water, removed much of the Vitamin D from the surface of human skin.** Helmer AC, Jensen CH. Vitamin D precursors removed from the skin by washing. Studies Inst. Divi Thomae, 1937, 1:207–216. > > Holick, et al’s, landmark 1980 study showing most human Vitamin D production occurs in the deep epidermis was incomplete. It was based on surgically obtained (and assumedly surgically prepped) skin samples that had any remaining surface oils removed by washing with hot water. Indeed, to accurately address the question of where Vitamin D is made, one would need to obtain unwashed human skin, difficult to do even from cadavers.8 > > It appears to me that t\*\*he percentage of Vitamin D made on the surface of the human skin, compared to that made inside the skin, is unknown at this time \*\*and in need of additional and careful research. Furthermore, if the percentage made on the surface is significant, studies of cutaneous Vitamin D production in modern humans—unless from skin that went unwashed for several weeks—will not give accurate estimates of Vitamin D production in early man. Thus, these studies cannot give an accurate estimate of the “natural” 25(OH)D levels present when the human genome evolved in Northeast Africa. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [October 25, 2013, 4:12pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/33 "2013-10-25T16:12:19Z")
How would vitamin D on the surface of the skin get into the body? Regards, Shodan ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 25, 2013, 4:28pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/34 "2013-10-25T16:28:06Z")
Well transdermal absorption _is_ possible and a fat soluble vitamin in an oil is a good vehicle for that. That said, even IF it turned out that some portion of vitamin D from sun exposure was made in surface oils that needed to be present for extended periods of time to be absorbed, the amount of vitamin D made _within_ the skin, with oils washed off afterwards, is _ample_ after even brief exposures to adequate sunlight. You can bathe after modest sun exposre without worry that it will negate adequate impact on vitamin D production. The open question is how to balance the vitamin D production benefit from the increased cancer risk harm: what constitutes appropriate modest sun exposure? ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [October 25, 2013, 4:30pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/35 "2013-10-25T16:30:32Z")
nm ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 25, 2013, 8:04pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/36 "2013-10-25T20:04:11Z")
I also found [this article](http://archinte.jamanetwork.com/article.aspx?articleid=414878), following trends in vitamin D levels. Independent of the increase caused by definition creep, there is real decrease in vitamin D levels across all groups both pooled and by subgroup analysis. Men and youth have dropped the biggest from 1988-1994 period to the 2001-2004 one, but all subgroups dropped. Using the under 30 defintion of vitamin D insufficiency > [@](#): > > The current analysis describes a much higher prevalence (77% during NHANES 2001-2004) of vitamin D insufficiency in the US population than previously reported … We found that the mean serum 25(OH)D level in the US population dropped by 6 ng/mL from the 1988-1994 to the 2001-2004 data collections. This drop was associated with an overall increase in vitamin D insufficiency to nearly 3 of every 4 adolescent and adult Americans. Although differences by age and sex have equalized, racial/ethnic differences have persisted and may help to explain known racial/ethnic disparities in cardiovascular disease, cancer, and other major health conditions. Nearly all non-Hispanic blacks (97%) and most Mexican-Americans (90%) now have vitamin D insufficiency. ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [October 25, 2013, 10:52pm UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/37 "2013-10-25T22:52:07Z")
> [@robert\_columbia](#): > > Is “getting more sunlight” a meaningful treatment for most Vitamin D deficiencies, or are we talking about problems with the body just not using the sunlight it’s getting? 19th century novels are replete with protagonists who are advised by their doctors to move to a different climate - is this a case where “Take a trip someplace sunny - I don’t know, Hawaii maybe, or the South Pacific, or the Caribbean, or Key West, or Egypt maybe, but stay the hell away from Anchorage for a bit.” could really help? The op made a list of all the dietary D they are getting, then asked “what am i missing?” Sunlight is missing. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [October 26, 2013, 3:21am UTC](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097/38 "2013-10-26T03:21:01Z")
Well we also do not know whether or not Jim B. is obese or not, which again also can [play a role](http://www.medicalnewstoday.com/articles/256049.php). > [@](#): > > For each 10% increase in BMI there was a 4.2% drop in Vitamin D. [Previous page](https://boards.straightdope.com/t/i-have-vitamin-d-deficiency/672097.md?page=1)