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Sun exposure
Vitamin A is an intrinsic modulator of proliferation and differentiation in human epidermis, and may be destroyed by ultraviolet radiation (UVR) impinging on the skin. To identify the deleterious effects of a perturbed cellular vitamin A status, we investigated the endogenous retinoid concentrations and the metabolism of [3H]retinol and all-trans [3H]retinoic acid in cultured human keratinocytes and melanocytes exposed to UVR, using high performance liquid chromatography. Before UVR the retinoid content was similar in keratinocytes and melanocytes, but the uptake of [3H]retinol was three-fold higher and the uptake of [3H]retinoic acid was 10-fold higher in the melanocytes. In both cell types, UVR (UVA 360 mJ/cm2 plus UVB 140 mJ/cm2) instantaneously reduced the concentration of retinol by about 50% and that of 3,4-didehydroretinol by about 20%. The retinoid concentrations returned to normal within 1–2 days post-irradiation, despite there being no overt increase in the uptake of [3H]retinol or the biosynthesis of 3,4-didehydroretinol. However, in both types of irradiated cells, the accumulation of the biologically most active metabolite, all- trans [3H]retinoic acid, was about 60% higher than in control cells. Furthermore, the metabolism of authentically supplied [3H]retinoic acid was reduced, especially in irradiated keratinocytes, which probably contributed to the restoration of retinoid levels after UV exposure.
I believe in sunshine, but I also don't feel any need to overdo. It does stir things up. Mad men and Englishmen...
Quote from tim on August 24, 2023, 5:59 amVitamin A is an intrinsic modulator of proliferation and differentiation in human epidermis, and may be destroyed by ultraviolet radiation (UVR) impinging on the skin. To identify the deleterious effects of a perturbed cellular vitamin A status, we investigated the endogenous retinoid concentrations and the metabolism of [3H]retinol and all-trans [3H]retinoic acid in cultured human keratinocytes and melanocytes exposed to UVR, using high performance liquid chromatography. Before UVR the retinoid content was similar in keratinocytes and melanocytes, but the uptake of [3H]retinol was three-fold higher and the uptake of [3H]retinoic acid was 10-fold higher in the melanocytes. In both cell types, UVR (UVA 360 mJ/cm2 plus UVB 140 mJ/cm2) instantaneously reduced the concentration of retinol by about 50% and that of 3,4-didehydroretinol by about 20%. The retinoid concentrations returned to normal within 1–2 days post-irradiation, despite there being no overt increase in the uptake of [3H]retinol or the biosynthesis of 3,4-didehydroretinol. However, in both types of irradiated cells, the accumulation of the biologically most active metabolite, all- trans [3H]retinoic acid, was about 60% higher than in control cells. Furthermore, the metabolism of authentically supplied [3H]retinoic acid was reduced, especially in irradiated keratinocytes, which probably contributed to the restoration of retinoid levels after UV exposure.
There ya go, converting retinol to retinoic acid in the cells isn't the best idea.
But, "instantly". Uh, I hope not!!!
My sun avoidance is working wonders.
Quote from tim on August 24, 2023, 5:59 amVitamin A is an intrinsic modulator of proliferation and differentiation in human epidermis, and may be destroyed by ultraviolet radiation (UVR) impinging on the skin. To identify the deleterious effects of a perturbed cellular vitamin A status, we investigated the endogenous retinoid concentrations and the metabolism of [3H]retinol and all-trans [3H]retinoic acid in cultured human keratinocytes and melanocytes exposed to UVR, using high performance liquid chromatography. Before UVR the retinoid content was similar in keratinocytes and melanocytes, but the uptake of [3H]retinol was three-fold higher and the uptake of [3H]retinoic acid was 10-fold higher in the melanocytes. In both cell types, UVR (UVA 360 mJ/cm2 plus UVB 140 mJ/cm2) instantaneously reduced the concentration of retinol by about 50% and that of 3,4-didehydroretinol by about 20%. The retinoid concentrations returned to normal within 1–2 days post-irradiation, despite there being no overt increase in the uptake of [3H]retinol or the biosynthesis of 3,4-didehydroretinol. However, in both types of irradiated cells, the accumulation of the biologically most active metabolite, all- trans [3H]retinoic acid, was about 60% higher than in control cells. Furthermore, the metabolism of authentically supplied [3H]retinoic acid was reduced, especially in irradiated keratinocytes, which probably contributed to the restoration of retinoid levels after UV exposure.
Ok, now I have way more questions after deliberating on this.
This was an en vitro, or cell study.
What was the medium they used? Did it have a known quantity of RBP bound to Retinol? Or, free retinol? Did they look at the detox products?
In other words, there was no liver connected to the system, or skin dermal layers, or kidney...the immediate impacts of UVR (UVA / UVB) are very interesting, but I would question anything really beyond the initial minutes of the expirement.
I would love to read the paper, regardless. Your extract + the abstract does intrigue me!!!
Yep, I just find it interesting because it could help explain some of the short term negative effects of sun exposure. I'm sold on sun exposure as a whole. It's not just retinoic acid that is produced. UV produces retinoid decomposition products as well.
Sunbathing cons:
Riboflavin depletion (beef, low fat dairy)
Folate depletion (legumes)
Temporarily elevated levels of retinoic acid
Carcinogenic potential from retinoids reacting with UV
Sunbathing pros:
Significant vitamin A depletion
Reduces autoimmunity
Nitric oxide production, reduces blood pressure and significantly reduces rates of heart disease
Aside from skin cancer significantly reduces rates of most other cancers
UVB having a beneficial effect on a range of hormones including boosting testosterone
Vitamin D production
Effects on serotonin/melatonin, improves sleep
Become a "really tan man"
@tim-2 big con of sunbathing a lot is skin aging.. Especially if you have some antioxidant balance issues and/or some toxicity like vit A, iron, copper etc. the skin will age so fast on the sun it is crazy.. Good example are old people who are sunbathing a lot.. They look like burned roasted chicken..
Quote from tim on August 26, 2023, 6:15 amYep, I just find it interesting because it could help explain some of the short term negative effects of sun exposure. I'm sold on sun exposure as a whole. It's not just retinoic acid that is produced. UV produces retinoid decomposition products as well.
Sunbathing cons:
Riboflavin depletion (beef, low fat dairy)
Folate depletion (legumes)
Temporarily elevated levels of retinoic acid
Carcinogenic potential from retinoids reacting with UVSunbathing pros:
Significant vitamin A depletion
Reduces autoimmunity
Nitric oxide production, reduces blood pressure and significantly reduces rates of heart disease
Aside from skin cancer significantly reduces rates of most other cancers
UVB having a beneficial effect on a range of hormones including boosting testosterone
Vitamin D production
Effects on serotonin/melatonin, improves sleep
Become a "really tan man"
Sunbathing cons:
Riboflavin depletion (beef, low fat dairy) - Or just some Riboflavin, it's cheap and safe (?)
Folate depletion (legumes) - Yup
Temporarily elevated levels of retinoic acid - And other retinol metabolites. This may overwhelm tissues all over the body.
Carcinogenic potential from retinoids reacting with UV - Sadly, and I should have thought about this before embarking on sun exposure.
Additional -
Sunbathing pros:
Significant vitamin A depletion - I believe so, but I am going to try a different path here. Ozone bagging (and, maybe peroxide baths). The retinol depletion may be as significant, but more complete in the destruction.
Reduces autoimmunity - Temporary, the surge of repleting retinol seems to still occur as long as the liver/tissues have sufficient storage.
Nitric oxide production, reduces blood pressure and significantly reduces rates of heart disease. - A negative, actually. NO production can hurt someone in a hypervitaminosis A situation. Additionally, NO is a backup route, CO2 is the main vasodilator (I am told)
Aside from skin cancer significantly reduces rates of most other cancers - Yes, the Vit D created along with the IR / NIR helps the body fight cancers. As long as dangerous retinol metabolites are not being created.
UVB having a beneficial effect on a range of hormones including boosting testosterone - I have seen the evidence here, but I think it's more from the NIR/IR along with the temporary Vit A depletion.
Vitamin D production
Effects on serotonin/melatonin, improves sleep
Become a "really tan man" - HA! Yes! But, also become a prune someday unless Vit A is removed and collagen / elastin can be replenished!
"And other retinol metabolites. This may overwhelm tissues all over the body."
Retinoic acid is more toxic when in elevated amounts than any decomposition product (not really metabolites, more like the products of retinoids being lasered by photons) as far as I know because of it's hormonal nuclear receptor apoptosis inducing effects.
"Temporary, the surge of repleting retinol seems to still occur as long as the liver/tissues have sufficient storage."
Reduction of autoimmunity probably occurs with the depletion of liver stores.
"A negative, actually. NO production can hurt someone in a hypervitaminosis A situation. Additionally, NO is a backup route, CO2 is the main vasodilator (I am told)"
I don't see how. Can you explain a bit more or provide a reference? I'd be interested in your take on this:
https://www.ted.com/talks/richard_weller_could_the_sun_be_good_for_your_heart
"I have seen the evidence here, but I think it's more from the NIR/IR along with the temporary Vit A depletion."
There was a recent study showing that UVB has direct effects on hormone levels. Nothing to do with vitamin D either.
"Yes, the Vit D created along with the IR / NIR helps the body fight cancers. As long as dangerous retinol metabolites are not being created."
It's currently believed that it's the vitamin D but it's wrong because vitamin D supplementation has now been shown to be a complete failure. Serum calcidiol levels strongly anticorrelate with cancer rates but it turns out it's only a correlation, not a causation.
I doubt it's mostly IR. I think it's mostly UVB and UVA depleting vitamin A. Sounds like you've done more research on IR than me though.
"HA! Yes! But, also become a prune someday unless Vit A is removed and collagen / elastin can be replenished!"
By the time one is a prune one's wife may be happy one is because she is too!
But seriously UVB hardly even reaches the dermis, UVA is thought to create most of the aging effect. UVA intensity does not vary much through the day and does not vary much through the year (ignoring cloud cover) and most do not wear a wide brimmed hat when outside. Most of our concern with aging is to do with our face so UVA induced facial aging has more to do with just the number of hours being outside in a day than with doing a bit of deliberate sunbathing. If one cares about UVA induced aging they could wear a wide brimmed hat when outside or just minimize time spent outside. When sunbathing one can easily cover one's face too.
I do suspect that elevated retinoic acid levels are a bigger problem when it comes to skin aging.
Quote from tim on August 26, 2023, 8:39 am"And other retinol metabolites. This may overwhelm tissues all over the body."
Retinoic acid is more toxic when in elevated amounts than any decomposition product (not really metabolites, more like the products of retinoids being lasered by photons) as far as I know because of it's hormonal nuclear receptor apoptosis inducing effects.
"Temporary, the surge of repleting retinol seems to still occur as long as the liver/tissues have sufficient storage."
Reduction of autoimmunity probably occurs with the depletion of liver stores.
"A negative, actually. NO production can hurt someone in a hypervitaminosis A situation. Additionally, NO is a backup route, CO2 is the main vasodilator (I am told)"
I don't see how. Can you explain a bit more or provide a reference? I'd be interested in your take on this:
https://www.ted.com/talks/richard_weller_could_the_sun_be_good_for_your_heart
"I have seen the evidence here, but I think it's more from the NIR/IR along with the temporary Vit A depletion."
There was a recent study showing that UVB has direct effects on hormone levels. Nothing to do with vitamin D either.
"Yes, the Vit D created along with the IR / NIR helps the body fight cancers. As long as dangerous retinol metabolites are not being created."
It's currently believed that it's the vitamin D but it's wrong because vitamin D supplementation has now been shown to be a complete failure. Serum calcidiol levels strongly anticorrelate with cancer rates but it turns out it's only a correlation, not a causation.
I doubt it's mostly IR. I think it's mostly UVB and UVA depleting vitamin A. Sounds like you've done more research on IR than me though.
"HA! Yes! But, also become a prune someday unless Vit A is removed and collagen / elastin can be replenished!"
By the time one is a prune one's wife may be happy one is because she is too!
But seriously UVB hardly even reaches the dermis, UVA is thought to create most of the aging effect. UVA intensity does not vary much through the day and does not vary much through the year (ignoring cloud cover) and most do not wear a wide brimmed hat when outside. Most of our concern with aging is to do with our face so UVA induced facial aging has more to do with just the number of hours being outside in a day than with doing a bit of deliberate sunbathing. If one cares about UVA induced aging they could wear a wide brimmed hat when outside or just minimize time spent outside. When sunbathing one can easily cover one's face too.
I do suspect that elevated retinoic acid levels are a bigger problem when it comes to skin aging.
For the NO issues, Weak Therefore Strong has talked quite a bit about it on her channel. Obviously NO is useful, but it appears to be a Goldilocks situation, especially during high rates of Vitamin A detox periods.
https://www.youtube.com/watch?v=8WyVFxSkZ9A
Honestly, it's a new idea to me, but it does make logical sense. Honestly, I don't know if the elevation in NO is that big of a deal from sun exposure. It's probably a bigger thing for NO inducers.
Agreed on the Vitamin D3 associations / correlations. It's more likely that the outcomes people with higher Vitamin D3 levels in the blood have are due to the sun exposure, and not to the actions of Vitamin D3 directly. In addition, the sun exposure method of Vitamin D3 involves a complex interplay with the kidneys outside of the liver's involvement. Taking Vitamin D3 directly impacts the liver, and from what I can see in the intervention studies, it negatively impacts the liver.
Auto-immunity reduction. I feel that it more comes from the ability to manage levels of retinoids inside the cells. This may come about from reduced peripheral levels, increase in RBP levels, and clear(er) ALDH, etc. pathways. When this occurs, less cell apoptosis and tissue disruption occurs, and that is what reduces the need for the immune system to intervene.
But, the jury is still out on the direct causes of auto-immunity. So, we all get to hypothesis.
My previous model came from incomplete breakdown of proteins in the diet causing runt peptides, to which the body made antibodies to destroy. And, the antibodies cross-matched with protein sequences in our tissues. Who knows, maybe that is a factor, as well.
I will watch the Ted talk. I have also listened to a lot of information from multi-sources that point to sun exposure as VERY helpful. I am both on the prowl looking for ways to "mitigate" my current situation, but currently believing I need to tamp down on it until Year 2 of the detox. (and, maybe till Year 3...depending on my progress)
Looking back, I started having sun exposure issues about 18 months before I became aware of Hypervitaminosis A. I have a feeling my peripheral levels of Vitamin A are a few notches above many, putting me more at risk. BUT, I could be horribly wrong. I wish there was some way to measure...
Near IR / IR has a lot of studies showing the benefits. It helps create "structured" water for capillary movement and cell boundary function, it definitely upregulates collagen formation, and so on.
I have a heat-lamp based sauna at home that I use for this purpose. Though, there is also something to say for the pulsed and squarer waves LEDs can make (and which some of the wavelength-based studies use).
A good deal of the suns wave's power is in the Near IR / IR area. A lot of that IR / Near IR is still coming in after the sun's UVB rays are nearly gone.
A separate note, but earlier in the year and in the Winter when I stopped Vit D3 low-dose supplementation, I got a Sperti UVB lamp (which still has UVA, but peaks in UVB). I had the worst dizziness and upticks in tinnitus from it later in the day and early evening. I have a sense the UVA / UVB power far exceeds the sun's UVA / UVB power. I didn't correlate the two at the time. I just thought it was a byproduct of a phase of Vit A detox...