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The scientific consensus tends to suggest a serum level of Vit D ~ 30 ng/mL as optimal. Bone abnormalities are expected with levels < 12 ng/mL. However, studies

The scientific consensus tends to suggest a serum level of Vit D ~ 30 ng/mL as optimal. Bone abnormalities are expected with levels < 12 ng/mL. However, studies looking at serum levels in otherwise healthy individuals show most people at <20 ng/mL. My take on the reports is that you want supplementation if it's below 10 ng/mL, with diminishing returns past that. The supplementation required to achieve 30 ng, or even 20 ng/mL for most people probably isn't worth it, and with unintended health consequences. Brown and black people likely have significantly lower "healthy" levels that don't warrant supplementation.

gridlockd 6y ago
> The supplementation required to achieve 30 ng, or even 20 ng/mL for most people probably isn't worth it, and with unintended health consequences. [citation needed] Safe upper limit is considered 4000 IU daily which will get you up there (and beyond) easily and is very affordable. For comparison, spending a while in the sun with your upper body exposed is easily 10,000 IUs for a light skinned person. > Brown and black people likely have significantly lower "healthy" levels that don't warrant supplementation. [citation desperately needed] Dark-skinned people are generally advised to supplement.
- valarauko 6y ago
  Like I said in the comment, this is my take on reports, not the current scientific consensus. About the desperately needed citations, let's start from these two: https://pubmed.ncbi.nlm.nih.gov/17413106/ https://pubmed.ncbi.nlm.nih.gov/17413106/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ The first is a study in South Indians. Even among rural workers spending long hours in the tropical sun, the study finds >80% of people had Vit D levels below the 'sufficiency' level of 30 ng/mL, in this otherwise healthy cohort. 44% of them had levels below 20 ng/mL. While this study doesn't report bone density, other studies on rural Indians suggest the osteoporosis prevalence at ~ 1% of the non-elderly population. There are no long term follow up studies in the rural indian population, but it's a reasonable assumption that individuals with very low Vit D levels (ie, < 12 ng/mL) were more likely to develop osteoporosis later in life. The study also reports low dietary calcium and high intake of dietary phytate, which are suspected to reduce circulating vit D levels. Do these necessarily lead to long term harm? It doesn't seem like it. Other reports suggest that lower bone density among rural Indians is most strongly linked to lower lean muscle mass. Greater the load bearing exercise, the better the bone density. The second study is among healthy blood donors in Nairobi, with 95% of subjects with Vit D levels between 12.73–22.07. In both studies, the participants live in tropical environments exposed to high levels of sunshine. By setting the optimal level of Vit D at 30 ng/mL, it pathologizes these otherwise healthy subjects. The concern is that the long term supplementation required to achieve 30 ng/mL would have unintended consequences, such as inappropriate calcification. As the Nairobi study points out, while low levels of Vit D are linked high levels of parathyroid hormone, beyond a certain point increasing vit D levels are linked to higher PTH levels. PTH leaches calcium out of the skeletal reserves and raises calcium levels in the blood. The deleterious effects of Vit D hypervitaminosis are due to high circulating levels of calcium. The Nairobi study shows that the lowest PTH levels were associated with vit D levels ~ 30 ng/mL, while individuals with vit D of 50 ng/mL had PTH levels similar to those with Vit D levels around 15 ng/mL. From the figure in the paper, it looks like if the goal is to minimise PTH, vit D levels < 15 ng/mL are sufficient. Which brings me to my initial assertion: brown and black people with plenty of sun exposure have naturally lower levels of circulating Vit D, with the average around 20 ng/mL. The Nairobi study points out that greater sun exposure did not significantly increase Vit D levels in this group. They do not seem to suffer greatly elevated levels of bone abnormalities due to this, or any other obvious health concerns. To me, this is suggestive that these levels are naturally equilibrated to be in the 20 ng/mL range, and attempts to push them higher might be deleterious. Setting the standard at 30 ng/mL unnecessarily pathologizes these otherwise healthy people, encouraging supplementation, which is not without health risks. Dark skinned people who live in high latitudes probably need greater supplementation than their light skinned neighbours, which is reasonable.
andy_ppp 6y ago
Yes I'd like to see studies that show what happens if you have higher than 30ng/mL and if these people are on average are happier, fight infection better, lower cancer rate etc. I was saying in my comment we don't have the studies to back up that your 30ng/ml is 100% correct. Unless you can point to studies "scientific consensus" is merely hearsay.
- valarauko 6y ago
  To the point about scientific consensus: https://doi.org/10.1007%2F978-0-387-77574-6_5 https://doi.org/10.1007%2F978-0-387-77574-6_5 The authors suggest that 30 ng/mL seems like the sweet spot for most health outcomes. Higher levels (~ 50 ng/mL) might be beneficial for fighting cancer, but the risks associated with the prolonged supplementation is unclear, which is why they do not recommend it. Something to keep in mind is that high levels of vit D are linked with high levels of circulating calcium, which is a problem. Protocols that advocate high Vit D doses, like the Coimbra Protocol for autoimmune diseases (100,000 IU per day), try to keep calcium levels low. The Coimbra Protocol tries to find the Vit D dose that minimises parathyroid hormone levels, and needs a diet practically calcium free to be safe. PTH causes calcium levels in the blood to go up, leading to kidney damage and inappropriate calcification. Outside of an extreme setting like the Coimbra Protocol, while PTH is inversely linked to Vit D levels, beyond a certain point rising Vit D levels cause PTH levels to go up. This suggests that there exists a sweet spot of circulating vit D that minimises PTH levels. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ This study among healthy subjects in Nairobi found that the lowest PTH levels were associated with a vit D level around 30 ng/mL.

gridlockd 6y ago

> The supplementation required to achieve 30 ng, or even 20 ng/mL for most people probably isn't worth it, and with unintended health consequences. [citation needed] Safe upper limit is considered 4000 IU daily which will get you up there (and beyond) easily and is very affordable. For comparison, spending a while in the sun with your upper body exposed is easily 10,000 IUs for a light skinned person. > Brown and black people likely have significantly lower "healthy" levels that don't warrant supplementation. [citation desperately needed] Dark-skinned people are generally advised to supplement.

valarauko 6y ago
Like I said in the comment, this is my take on reports, not the current scientific consensus. About the desperately needed citations, let's start from these two: https://pubmed.ncbi.nlm.nih.gov/17413106/ https://pubmed.ncbi.nlm.nih.gov/17413106/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ The first is a study in South Indians. Even among rural workers spending long hours in the tropical sun, the study finds >80% of people had Vit D levels below the 'sufficiency' level of 30 ng/mL, in this otherwise healthy cohort. 44% of them had levels below 20 ng/mL. While this study doesn't report bone density, other studies on rural Indians suggest the osteoporosis prevalence at ~ 1% of the non-elderly population. There are no long term follow up studies in the rural indian population, but it's a reasonable assumption that individuals with very low Vit D levels (ie, < 12 ng/mL) were more likely to develop osteoporosis later in life. The study also reports low dietary calcium and high intake of dietary phytate, which are suspected to reduce circulating vit D levels. Do these necessarily lead to long term harm? It doesn't seem like it. Other reports suggest that lower bone density among rural Indians is most strongly linked to lower lean muscle mass. Greater the load bearing exercise, the better the bone density. The second study is among healthy blood donors in Nairobi, with 95% of subjects with Vit D levels between 12.73–22.07. In both studies, the participants live in tropical environments exposed to high levels of sunshine. By setting the optimal level of Vit D at 30 ng/mL, it pathologizes these otherwise healthy subjects. The concern is that the long term supplementation required to achieve 30 ng/mL would have unintended consequences, such as inappropriate calcification. As the Nairobi study points out, while low levels of Vit D are linked high levels of parathyroid hormone, beyond a certain point increasing vit D levels are linked to higher PTH levels. PTH leaches calcium out of the skeletal reserves and raises calcium levels in the blood. The deleterious effects of Vit D hypervitaminosis are due to high circulating levels of calcium. The Nairobi study shows that the lowest PTH levels were associated with vit D levels ~ 30 ng/mL, while individuals with vit D of 50 ng/mL had PTH levels similar to those with Vit D levels around 15 ng/mL. From the figure in the paper, it looks like if the goal is to minimise PTH, vit D levels < 15 ng/mL are sufficient. Which brings me to my initial assertion: brown and black people with plenty of sun exposure have naturally lower levels of circulating Vit D, with the average around 20 ng/mL. The Nairobi study points out that greater sun exposure did not significantly increase Vit D levels in this group. They do not seem to suffer greatly elevated levels of bone abnormalities due to this, or any other obvious health concerns. To me, this is suggestive that these levels are naturally equilibrated to be in the 20 ng/mL range, and attempts to push them higher might be deleterious. Setting the standard at 30 ng/mL unnecessarily pathologizes these otherwise healthy people, encouraging supplementation, which is not without health risks. Dark skinned people who live in high latitudes probably need greater supplementation than their light skinned neighbours, which is reasonable.

andy_ppp 6y ago

Yes I'd like to see studies that show what happens if you have higher than 30ng/mL and if these people are on average are happier, fight infection better, lower cancer rate etc. I was saying in my comment we don't have the studies to back up that your 30ng/ml is 100% correct. Unless you can point to studies "scientific consensus" is merely hearsay.

valarauko 6y ago
To the point about scientific consensus: https://doi.org/10.1007%2F978-0-387-77574-6_5 https://doi.org/10.1007%2F978-0-387-77574-6_5 The authors suggest that 30 ng/mL seems like the sweet spot for most health outcomes. Higher levels (~ 50 ng/mL) might be beneficial for fighting cancer, but the risks associated with the prolonged supplementation is unclear, which is why they do not recommend it. Something to keep in mind is that high levels of vit D are linked with high levels of circulating calcium, which is a problem. Protocols that advocate high Vit D doses, like the Coimbra Protocol for autoimmune diseases (100,000 IU per day), try to keep calcium levels low. The Coimbra Protocol tries to find the Vit D dose that minimises parathyroid hormone levels, and needs a diet practically calcium free to be safe. PTH causes calcium levels in the blood to go up, leading to kidney damage and inappropriate calcification. Outside of an extreme setting like the Coimbra Protocol, while PTH is inversely linked to Vit D levels, beyond a certain point rising Vit D levels cause PTH levels to go up. This suggests that there exists a sweet spot of circulating vit D that minimises PTH levels. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6180659/ This study among healthy subjects in Nairobi found that the lowest PTH levels were associated with a vit D level around 30 ng/mL.