I would definitely worry about overdosing on Vitamin D from supplements, and the sun. However, only if there is Vitamin D Receptor (VDR) dysregulation, would I worry about Vitamin D from the sun. It is firstly helpful to better understand Vitamin D metabolism: Keratinocytes in the skin can turn 7-dehydrocholesterol straight into 1,25-D (The Active form of Vitamin D). Supplementation differs from sun exposure with regards to Vitamin D, because supplements for the most part seem to turn into 25-D (The Inactive form of Vitamin D). 1,25-D is the Active Metabolite of Vitamin D, and it activates the VDRs. 25-D is the inactive form of Vitamin D, and it binds up and inactivates the VDRs, when its levels become elevated. Sun exposure can end up as 25-D as well, depending on the individual, and their individual health. Vitamin D metabolism goes like the following, with the exception of skin keratinocytes being able to convert 7-dehydrocholesterol (7-DHC) straight into 1,25-D. 7-DHC --> Vitamin D3 --> 25-D --> Theoretically then to 1,25-D, via the kidney and the liver.There is an alternative hypothesis about Vitamin D
: 25-D (which supplements, dietary sources of Vitamin D and some sun exposure turns into) has been shown through molecular modeling (which has a greater than 90% chance of being right) to bind and inactivate the Vitamin D Receptors (VDRs) (Proal, 2007). The result is that the innate immune system is blocked from working effectively, and expressing Anti Microbial Peptides (AMPs). When this happens, the immune system no longer fights the bacteria, resulting in a temporary
alleviation of symptoms.
So when the person said the sun cures the Acne, this might be part of what is happening: sun exposure also causes a lot of "backed up" 25-D production, because aside from the keratinocytes converting 7-dehydrocholesterol directly to 1,25-D, UVB also converts 7-dehydrocholesterol to Pre-Vitamin D, which ends up as 25-D, which blocks the VDRs from fighting the bacterial infection, and the inflammation ceases (temporarily). This makes some sense, because the Acne comes back...right? Such a rapid reduction in symptoms, together with only a temporary alleviation seems to suggest to me that the infection still exists, so the immune system was just prevented from fighting it effectively, and inflammation ceased. Apparently it is when bacteria die, that inflammation and toxic by-products are formed (Proal, 2007). Furthermore, the disease in many cases, if not all cases, seems to come back worse after this. It is just not practical to go and "cure / temporarily alleviate" Acne symptoms every day with the sun is it?
It is good to better understand Vitamin D metabolism, as molecular bio-researchers apparently know more about this than most people (Proal, 2007). 25-D levels are checked for Vitamin D "deficiencies" when these may be perfectly normal levels, with low levels of 25-D seen by some to be very optimal, to keep the innate immune system from being blocked up / dysregulated. 1,25-D levels are normally very high in diseased individuals (Proal, 2007), and it is these levels that are not checked properly it seems. It seems that 1,25-D levels are rarely checked with regards to Vitamin D (Proal, 2007), which seems to be a concern, because these are the levels of the active metabolite of Vitamin D, whereas what gets checked is 25-D, the inactive
form of the Vitamin D metabolite.
This is according to newer molecular modeling research, and this seems to show that basically; 25-D supplementation is counterproductive and seems to perform little to no useful service in the body. The new molecular modeling research seems to be saying that 25-D is an immunosuppressive steroid
, acting on steroid
receptors, once its levels get elevated (Proal, 2007). Steroids are generally known to be immunosuppressive, meaning infectious disease rates tend to be high with steroid use.
Keeping in mind this was only a 21 day study, when it gets said "Vitamin D Improves...Skin's Immune System", I think a greater understanding of "Vitamin" D metabolism would prove greatly useful. 1,25-D is an active immunomodulatory hormone, and its levels are directly increased through sun exposure. Proal (2008) presented on auto-immune disease at the 6th International Congress on Autoimmunity held in Porto, Portugal, and stated that androgen receptors are related to: cathelicidin, whereas VDRs are not. Cathelicidin was raised initially in this topic by the topic starter. Proal (2008) states that 1,25-D elevation, due to VDR dysregulation can result in hormonal imbalances, and other autoimmune diseases, which is a concern. The VDR "dysregulation" referred to is a result of pathogenic infection, and elevated 25-D levels, from fortified food and supplementation (Proal, 2007). Proal (2008) demonstrates that the high 1,25-D levels, which occur only because Vitamin D is now dysregulated
due to VDR blockage can cause issues with androgen receptors, which are supposedly responsible for the production of the antimicrobial peptide raised here: cathelicidin.
Therefore that is why "Vitamin" D relates to cathelicidin, because 1,25-D levels which are raised due to VDR dysregulation
, block the proper expression of the antimicrobial peptides, including the ones expressed by androgen receptors, such as: cathelicidin. Oral supplementation with Vitamin D, as was done in the study raised here then results in higher 25-D levels, which more efficiently might block the VDRs I suppose, reducing the expression of 1,25-D temporarily, which might allow the Androgen Receptors, previously prevented from expressing AMPs such as cathelicidin, to function again, due to the the high 1,25-D levels acting in a negative way for nuclear receptor docking, all resulting from the VDR dysregulation.
What seems to be important here is that androgens relate to Acne, but Cathelicidin, spoken of here, also is related to androgen receptors (Proal, 2008). "Vitamin" D relates to androgens, when Proal (2008) shows us that raised 1,25-D due to VDR dysregulation inteferes with proper androgen receptor expression of anti microbial peptides, including the proper expression of : cathelicidin (Proal, 2008). I hypothesise at this stage that the positive results reported here are due to greater VDR blockage than before, resulting in decreased 1,25-D expression (which for sure would already be dysregulated - the real issue here), which frees up the Androgen Receptors (ARs) to express more of cathelicidin - temporarily.
In the long run, also an issue raised by this study: Proal (2007) and others agree that VDR dysregulation will only further worsen with "supplementation", of this "immunosuppressive steroid", which has profound effects on the innate immune system. Essentially, it switches it off. VDRs are the lynchpin of the innate immune system (Proal, 2007). You do not want to switch off the innate immune system. The only reason cathelicidin was helped here in this study was because, in my mind, 1,25-D levels were way too high due to already pre-existing pathogenic infection and 25-D VDR blockage (Dysregulation), and the dysregulated high levels of 1,25-D affected the AR's from properly expressing AMPs, such as: cathelicidin. ARs express the AMP cathelicidin, but not VDRs, they are responsible for other AMPs, but not cathelicidin. Vitamin D supplementation, which increased 25-D blocked up excessive 1,25-D expression interfering with ARs, and the formation of its AMPs, which included: cathelicidin. When the extra levels of 25-D stimulated by supplementation with Vitamin D blocked up the VDRs, preventing over-expression of 1,25-D temporarily, high 1,25-D levels were then not as active to prevent proper nuclear receptor docking with such other receptors as Androgen Receptors, which are responsible for AMPs such as cathelicidin.
That is my current position on the matter.Healthoid:
Why then does UV damage the skin's DNA, leading to skin cancer, if we were meant to be outdoors all the time? This is not good, caucasians in Australia (like me) have the highest amount of melanoma's and other skin cancers, the sun is great, UV is not.
Proal, A. 2007, The Truth About Vitamin D: Fourteen Reasons Why Misunderstanding Endures, Accessed October 2008, http://bacteriality....09/15/vitamind/.
Proal, A. 2008, Bacteriality - Exploring Chronic Disease, Accessed October 2008, http://bacteriality.com.