Hate to say it, since I have been a Matt K fan, but I disagree with a lot that was said in that video.

https://www.scientificamerican.com/article/how-much-vitamin-d-do-you-need-to-stay-healthy/

Please note ā€” Vitamin D is important to monitor - BUT it isnā€™t fixed by supplementing it - you still have the same bad outcomes.

Measure it unsupplemented. If low, you have risks ā€” work on getting a therapeutic D without supplementation - BECAUSE youā€™ll supplement, think you are all good because your numbers look great ā€¦ but youā€™ve still not fixed what caused the low vitamin D level which is what the active ingredient is.

All of the RCTs show supplementation of people with low vitamin D donā€™t help one bit ā€” but falsely will lull people into thinking they are fine when supplementing.

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I know Iā€™m low w no supplementation. What does one do other than being in the sun?

This is the challenge, adequate UV exposure (without getting skin cancer - so large % of your body exposed for not too long), exercise increases vitamin D - possibly due to increased absorption. There are lists of food that have this in it - for vegans - itā€™ll be limited to mushrooms. The challenge is whether the food consumption of it is any different than taking a supplement? Then there are foods that simply have it added, in supplement form - so that wonā€™t be different - but naturally occurring is it different and is there some co-factor we arenā€™t measuring that comes along with it when naturally occurring?
We donā€™t know, but it would seem like simply normalizing the number by supplements doesnā€™t have the beneficial effect youā€™d hope.

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Whatā€™s the difference from getting vitamin D from sun, food, or supplements? You just skip the first two steps in this figure.
image

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Thank you for your contribution here because Iā€™ve never heard this! And argh, I donā€™t eat many mushrooms, but I did just get mushroom powder (Iā€™ll look that up to see if it helps). And bigger argh, my entire life is about NOT getting any sun (to make up for going to school in Florida and thinking spf 4 was way too high and using foil blankets!!!) Thx again

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Vegan D3 supplements are from lichen, anyway there is no difference from getting vitamin D from sun, supplements, etc, so I would just avoid risk for skin cancer and the certainty of skin aging and take a supplement.

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Is this one of those things where they test supplementing but donā€™t stratify by the level achievedā€”or do they find that those who actually measure at a threshold level with supplementation fare differently than those who measure at the same level without supplementation.

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Iā€™m going to dig in a bit on this next week when I have some time to research further. I find a mixed bag here. Iā€™m not arguing that the vitamin D from food is different than supplements - but as with other examples of tracking nutrients, it is possible another thing is common in the foods that naturally have vitamin D that is the actual active factor. I suspect it may be also related to activity and sun exposure - which probably correlate with overall metabolic health.

The initial studies on supplementation for severe covid were all negative, but I was just looking and I see now we actually have some good data that for this we have some positive data now - so potentially we have at least one condition it seemed to have a positive outcome in.

The criticism of just supplementing everyone and not tracking is a valid one, but weā€™d expect an effect as we know that a high % of people are deficient, and significantly improving levels would have occurred even if not measured. The lack of effect for traditional items that Vitamin D being low is associated with is problematic.

It is benign to supplement, but would seem better to see if we can get the individual do get the level up without doing this through traditional mechanisms ā€¦ and if this is a fail, then supplement, if successful, would seem likely superior.

Just my thoughts on the evidence today. Again, Iā€™m going to do a blog on this upcoming, and need to really dig in on this, and might change my mind.

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What so many of us on this forum are grappling with is that causal inference is really hard. When you are trying to understand how to improve the function of a complex system, you donā€™t have an easy task in front of you. Looking forward to your further insights.

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Wouldnā€™t be wild if turned out that Previtamin D3 actually serves a purpose other than just being a metabolite ? Evolution forces efficiency.

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As subject matter gets buried and or mixed.

Back in July 2022 on this forum we had a long discussion on ā€œVitamin Dā€

Review the thread, had 47 post

Start of the thread

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You also need enough magnesium to fully absorb vitamin D. And, most people are low on magnesium.

Iā€™ve added magnesium citrate to my supplements so hopefully itā€™ll being my vitamin D levels up to par.

Iā€™m just shocked that 5000 IUs daily only bumped me up less than 10 pts from low 20s to 30 (barely sufficient). Hopefully 10,000 IUs plus magnesium will do the trick.

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Great to hear, look forward to seeing it!

FYI: Karl Phleger is one of the top longevity guys in Silicon Valley and after looking into the topic a LOT is a big proponent of Vit D supplementation to optimal levels.

He has a long and rich series of twitter threads on the topic, pointing to many key studies and putting them in context of what he thinks they say and donā€™t say.

Might be a valuable source to cross reference with as you build your blog post.

Here is a piece from his Linked-in:

Common simple D RCT flaws:

  • Not starting w/ subjects w/ low levels.
  • Not using high enough dose to meaningfully change status (eg resolve deficiency). Esp true w/ overweight subjects who need higher doses.
  • Not waiting long enough for levels to rise before measuring outcomes.

Now a new trial called Target-D tries to do the right thing by repeatedly testing 25OHD until a prespecified target (40ng/ml) is achieved & early data presented at American Heart Associationā€™s Novā€™23 meeting vindicates the criticisms of the prior trials.

Outcome data not mentioned (prob not avail yet) but data f/ early dosing still shows the issues:

On dose: ā€œ90% [of subjects] required some level of Vitamin D dosing. Of those, 86.5% required more than 2000 IU daily [VITAL study dose] and 14.6% required more than 10,000 IU dailyā€

On how long it took: ā€œLess than 65% achieved over 40 ng/mL at three months. Another 25% of patients required six months or more of dosing titrationā€ So longer than most D RCTs wait to measure outcomes, usually w/o testing levels achieved. Shows mid-trial testing is important.

ā€œOur findings here show that just giving patients some Vit D does not help them achieve optimal levelsā€

Just b/c a trial is big doesnā€™t mean it answers the right question. Most failed D trials donā€™t negate the hypothesis that raising levels f/ low to sufficient improves health.

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@Neo Great post. I agree with you completely.

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I think there are limits to the rate at which the body can convert cholecaliciferol (D3) to calcifediol (25OHD - 25 Hydroxy Vitamin D).

I think that limit is somewhere in the range of oral consumption of cholecalciferol of 3,000-6,000 IU. It probably nudges up there.

This is from my experiments with weekly blood tests.

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What vitamin D level does Karl Phleger think is good? I think itā€™s a pretty safe supplement as long as itā€™s not taken monthly in very high doses, and itā€™s pretty cheap, so might as well get those D levels upā€¦ and it is a supplement so doesnā€™t require a lot of effort.

There is so too much information for a layman like me, so I will start to referring to expert opinion (who I believe is good), otherwise I am not going to do muchā€¦

Thatā€™s just speculation?

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@Neo, thanks for this. It is interesting how one getā€™s in their own sound chamber in regard to information. When I did my A4M boards, the clear education was test and supplement if low. I guess the good news for my patients is that is exactly what Iā€™ve done.

However, Iā€™ve been challenged by some pretty reasonable physicians on this approach. So looking at UpToDate and MedScape - and the Scientific American piece (albeit just trying to represent the medical literature, but not of the same level of medical writing as UpToDate) - the message is consistent - we have no evidence of benefit of supplementation, but low levels are bad.

The write-up on UpToDate is pretty sensible and very detailed, going condition to condition - each of pretty much stating that low Vitamin D levels are associated with worse outcomes in cancer, infection, autoimmune, cardiovascular, diabetes, all cause mortality. Along with that on each one ā€¦ a discussion that ā€œHowever, there are no convincing randomized trial data that vitamin D supplements can decrease cancer risk or prognosis, decrease the risk or severity of infections or autoimmune diseases, or decrease cardiovascular risks or metabolic diseases. In addition, there are no prospective studies to define optimal 25(OH)D levels for extra skeletal health. Thus, we do not suggest vitamin D supplementation above and beyond what is required for osteoporosis management.ā€

The problem is the studies done have problems.

We also have a fair history of targeting things and normalizing them artificially and not having the expected outcomes.

Iā€™m going to do the deep dive on this and generate a solid review. I suspect best approach is to test, if low work on normalizing naturally, retest in 3 months, if no acceptable improvement to goal, then supplement.

The problem is one cannot feasibly do the deep dive into everything, but this one, Iā€™m going to - and I appreciate the input, as I donā€™t think Iā€™m going to take the mainstream advice on this topic - which is to not supplement if low.

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@DrFraser I look forward to your findings. Vit D is a conundrum for the layperson. Iā€™ve spoken to scientists and medical professionals who say a range of things:

  • Vit d is only a marker of getting enough sunshine (sunshine provides more than vit d)
  • Vit d supplementation doesnā€™t solve any health problems (according to clinical trials)
  • Vit d studies have been done all wrong and canā€™t be trusted. Take Vit d just in case
  • stay out of the sun to avoid skin cancer (my dermatologist said this just yesterday).

I am working on my Vit d status as an overall indicator of health status (much like sex hormones), but I sure wish I understood the levers better. Iā€™m sure itā€™s more than taking a vit d supplement.

Involvement with other nutrients: vit A, vit c, magnesium, calcium

Involvement with mitochondrial health, nitric oxide capability, gut function.

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I look forward to your deep dive. My perspective is that getting Vit D from ultraviolet light (sunshine) is profoundly and fundamentally different from supplementation. Hence the total confusion and lack of clarity from all the supplementation studies. From the following article belowā€¦

There has been a lot of discussion as to whether ingesting vitamin D from the diet or from a supplement is the same as producing vitamin D3 in the skin. Because it takes approximately ~8 h for previtamin D3 in the skin to fully convert to vitamin D3[Citation26]
(https://www.tandfonline.com/doi/full/10.4161/derm.24494#),Citation27 and it takes additional time for the vitamin D3 to enter the dermal capillary bed this is at least 2 of the explanations for why it was observed that vitamin D3 produced in the skin last 2ā€“3 times longer in the circulation when compared with ingesting it orally (Fig. 16).Citation29 Furthermore when vitamin D3 is produced in the skin 100% of it is potentially bound to the vitamin D binding protein (Fig. 17). When vitamin D3 is ingested from the diet or supplement it gets incorporated into chylomicrons which are transported into the lymphatic system and then into the venous system were approximately 60% of the vitamin D3 is bound to the vitamin D binding protein and 40% is rapidly cleared in the lipoprotein bound fraction.Citation29

The source of the information is from a well cited (1548 "cited by "according to Google scholar) 58 page article: Wacker, M., & Holick, M. F. (2013). Sunlight and Vitamin D: A global perspective for health. Dermato-endocrinology , 5 (1), 51-108.

Well written and a good start for a debate on the topic.

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