Vitamin D deficiency may drive myopia, supplementing may prevent/treat it
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Vitamin D has become a bit of a controversial topic lately. While there is a lot of recent promising research demonstrating effectiveness of vitamin D supplementation for many serious conditions, at the same time there has been a significant push by certain groups (both pharma-affiliated and in the general population) to discredit vitamin D by promoting the idea that it is some kind of a poison, even at physiological/therapeutic doses, based on the fact that extremely high (and toxic) amounts of vitamin D are used as rat poison. If one peruses the literature on PubMed about this topic, it becomes quickly apparent that cases of vitamin D-induced hypercalcemia (the mechanism through which rats are killed with vitamin D overdose) are very, very rare and amount to probably no more than a few hundred annually in a country with the population of US. Even then, the cases invariably describe absurd dosing regimens, often with the intent of suicide, and as such are not relevant to the clinical usage of vitamin D in doses with well-established safety.
Be that as it may, the study below presents some very interesting findings. Namely, that one of the most common ocular conditions – myopia – may not only be directly caused by vitamin D deficiency (widespread in the general population), but may also be treatable by vitamin D supplementation. The study used calcitriol as the active intervention, but the same effects should be achievable with cholecalciferol(vitamin D3), with the latter also running much lower risk of causing hypercalcemia. The treatment lasted 4 weeks and the human-equivalent dose converted from calcitriol into cholecalciferol was 160 IU / kg (bodyweight) daily. That means for most people a daily dose of 10,000 IU – 12,000 IU vitamin D3 should be able to replicate the study design and its findings. That dose is considered high but is on par with what doctors prescribe in cases of vitamin D deficiency (50,000 IU – 75,000 IU once weekly).
https://www.nature.com/articles/s41598-024-62131-x
“…The annual increase in myopia prevalence poses a significant economic and health challenge. Our study investigated the effect of calcitriol role in myopia by inducing the condition in guinea pigs through form deprivation for four weeks. Untargeted metabolomics methods were used to analyze the differences in metabolites in the vitreous body, and the expression of vitamin D receptor (VDR) in the retina was detected. Following form deprivation, the guinea pigs received intraperitoneal injections of calcitriol at different concentrations. We assessed myopia progression using diopter measurements and biometric analysis after four weeks. Results indicated that form deprivation led to a pronounced shift towards myopia, characterized by reduced choroidal and scleral thickness, disorganized collagen fibers, and decreased scleral collagen fiber diameter. Notably, a reduction in calcitriol expression in vitreous body, diminished vitamin D and calcitriol levels in the blood, and decreased VDR protein expression in retinal tissues were observed in myopic guinea pigs. Calcitriol administration effectively slowed myopia progression, preserved choroidal and scleral thickness, and prevented the reduction of scleral collagen fiber diameter. Our findings highlight a significant decrease in calcitriol and VDR expressions in myopic guinea pigs and demonstrate that exogenous calcitriol supplementation can halt myopia development, enhancing choroidal and scleral thickness and scleral collagen fiber diameter.”
“…Given the rising incidence of myopia, which now stands as a principal contributor to visual impairment globally, the quest for efficacious myopia control methods remains critical19. Although low-dose atropine has shown effectiveness, its application is limited by adverse effects and a rebound effect post-discontinuation20,21. Consequently, identifying new, safer, and more efficacious strategies for myopia management is crucial. Our study confirmed the role of calcitriol and VDR in the onset and progression of myopia. We have established that exogenous calcitriol supplementation notably curbs myopia progression and alleviates reductions in choroidal and scleral thickness as well as scleral diameter, these findings provide new insights into the development of new drugs for myopia.”
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@haidut I think its mediated by copper (vitamin D helps copper import through ctr1, copper major role in eye health as shown by a woman restoring her eyesight from 20/400 to 20/25 when she fixed her deficiency https://pubmed.ncbi.nlm.nih.gov/26828841/)
a nice study here showing this which stabilized eye health during degeneration & even slightly improved in humans, but not for the group where ceruloplasmin goes down with the ctr1 increase. showing it was mediated by copper , *(We need both atp7a and ctr1 expressed for proper copper absorption and movement, speculating for the group where ceruloplasmin lowered maybe they lacked thyroid hormone or vitamin a (atp7a) so net effect they stopped exporting copper and got a cellular overload instead? or simply didnt have enough copper in diet for the vit D to help raise it. or some tissues got it but lack of circulating copper to replenish where it was needed as wasnt exporting from liver enough. OR their thyroid signalling dropped which lowered ceruloplasmin.
both groups increased ctr1 & only the unresponsive groups ceruloplasmin fell so didnt get the eye health benefit. the group who kept stable ceruloplasmin with an increase of ctr1 to import it into cells gained improved eye health) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9804020/We report, for the first time, to the best of our knowledge, that the serum levels of the Cu carrier ceruloplasmin are largely below reference levels in KC adolescent patients. In this scenario, we found that Vit D supplementation enhances copper availability by increasing the expression of the principal Cu membrane transporter CTR1 and the chaperone CCS
Interestingly, average BSCVA (logMAR) slightly improved after Vit D supplementation(i also think this plays a major role in schizophrenia - vit a / thyroid / vid d / copper connection will put up a thread of interesting findings)
*(i dont doubt that agenda you mentioned but its not only that in my experience, vitamin D for a subset of people can have negative effects aside from the hypercalcemia angle , i have gone through extremes from common amounts and digging into it found 1,25 vit D and the VDR (so vit d) can act to block mitochondrial respiration - i think people who react negatively to it e.g severe twitching are often hypothyroid and this is worsening low atp - vitamin D converts excessively to 1,25 in certain situations e.g inflammatory conditions through macrophages, hypothyroidism through low t3 signalling which is supposed to counter 1,25 , hyperthyroidism has low 1,25 conversion https://academic.oup.com/endo/article/154/2/609/2423282?searchresult=1 vit D likely has even more potent binding to thyroid receptors than even t3 https://pubmed.ncbi.nlm.nih.gov/8631908/ and the effect is to inhibit t3 effects (i think its supposed to be a protective mechanism to stop excess ROS for what the cell can handle, but can get out of control) (in other situations fixing low vit d levels can increase respiration / oxygen consumption though, confusing )
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I don't doubt that Vitamin D plays a role in preventing myopia. The problem with these studies gives the uninitiated a skewed view of the role of each vitamin or mineral or enzyme or hormone that plays a role in the upkeep of the many functions in our body.
The more important takeaway for me with each and every study that proves what each vitamin/mineral/enzyme/hormone/substance does, is that when it comes to summing it all up, is that it is better to assume that each and every one of these play a role in maintaining the optimal functionality of every part in our body. And to simplify our lives, it is best to start off by checking each box to eliminate any deficiency.
Instead of taking a boatload of nutrients via supplementation, one is better off getting it thru food, by ensuring one gets enough of the variety that ends up with one consuming these nutrients where they are most effectively absorbed as whole foods. As the nutrients allow the body to produce enzymes and hormones, we also can rely less on supplementing with enzymes and hormones and count on a healthy body to produce these protective substances.
My eyesight at an age where I should be wearing bifocals, is much much better than when I was a teenager. I am no longer wearing glasses and am not even required to use them to drive, something which I never expected to happen.
But my vitamin D alone being sufficient wasn't enough. I lived with enough exposure to sunshine and my tests show no vitamin deficiency. But from the metabolic improvements I have attained by following Peat's many advices, I have an abundance of CO2, which in reading one Peat's articles, speaks to being contributory to keeping the cornea clear and free from the onset of cataract and glaucoma. But vitamin D with an abundance of CO2 may not explain my eyesight improvement.
As I believe that since 2016, when I joined RPF, I adopted the habit of eating a serving of beef liver every week. It took awhile for me to regain the functionality of my eyes, and though I suspected it had improved but never bothered to confirm it, it was only when U had to renew my driver's license that I had an eye exam. To my surprise, I was told the need to wear glasses would be removed as a stipulation for me to drive.
You provide us with very useful studies that altogether form a cohesive backbone that pieces the meat together with Ray Peat's research and derivations from him connecting the dots into a whole field of bioenergetics. Without which we have much less dots to connect with, and which makes leas sense. Thanks for supplying us more ammo to dispel the myths around us.
I hope though, that the evolution if the field of bioenergetics would see us sharing more success stories.
Success is not as much the taking of individual substances as magic bullets. It is more a process of seeing each substance as a role player than a star that leads one to the championship and winning it. It is a team effort, and there is a process to it.
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@yerrag said in Vitamin D deficiency may drive myopia, supplementing may prevent/treat it:
I hope though, that the evolution if the field of bioenergetics would see us sharing more success stories.
Success is not as much the taking of individual substances as magic bullets. It is more a process of seeing each substance as a role player than a star that leads one to the championship and winning it. It is a team effort, and there is a process to it.
I totally agree.
