Vitamin D3(domofutu.substack.com)
domofutu.substack.com
Vitamin D3
https://domofutu.substack.com/p/vitamin-d3
5 comments
Great question and fair push-back. Two quick clarifications:
The ETCS isn’t a ratio scale. A 70 vs 68 isn’t “1.02× more true”; it’s a weighted confidence score that blends consistency of RCTs/meta-analyses, effect size, heterogeneity, external validity (who benefits), dosing clarity, and risk trade-offs. Small gaps (especially near band edges) should be read as “roughly comparable confidence,” not a meaningful quantitative jump.
Why 70 (“Strong, with nuance”) for fractures vs 68 (“Moderate-to-Strong”) for respiratory infections? Because the fracture claim is consistently positive when paired with calcium in older/institutionalized adults (clear population + pairing guidance), whereas the respiratory finding shows a modest, baseline-dependent benefit (strongest only when deficient; daily/weekly dosing beats bolus; more heterogeneity and large neutral trials in sufficient populations). Same neighborhood numerically, but the value proposition differs (i.e., Fractures: act when risk is high; pair D3 with calcium; practical, repeatable benefit; Respiratory: correct deficiency first; expect at most a modest protective effect, not population-wide gains).
To make this clearer going forward, I’ll add a short ETCS legend in each post and note that ≤3–5-point differences within a band are “near-ties.” Thanks for the nudge. This is exactly the kind of reader feedback that I'm looking for.
The ETCS isn’t a ratio scale. A 70 vs 68 isn’t “1.02× more true”; it’s a weighted confidence score that blends consistency of RCTs/meta-analyses, effect size, heterogeneity, external validity (who benefits), dosing clarity, and risk trade-offs. Small gaps (especially near band edges) should be read as “roughly comparable confidence,” not a meaningful quantitative jump.
Why 70 (“Strong, with nuance”) for fractures vs 68 (“Moderate-to-Strong”) for respiratory infections? Because the fracture claim is consistently positive when paired with calcium in older/institutionalized adults (clear population + pairing guidance), whereas the respiratory finding shows a modest, baseline-dependent benefit (strongest only when deficient; daily/weekly dosing beats bolus; more heterogeneity and large neutral trials in sufficient populations). Same neighborhood numerically, but the value proposition differs (i.e., Fractures: act when risk is high; pair D3 with calcium; practical, repeatable benefit; Respiratory: correct deficiency first; expect at most a modest protective effect, not population-wide gains).
To make this clearer going forward, I’ll add a short ETCS legend in each post and note that ≤3–5-point differences within a band are “near-ties.” Thanks for the nudge. This is exactly the kind of reader feedback that I'm looking for.
Good explain. Thanks. Also fascinating. In Oz, far more women than men get D3 and calcium looked at, because they're prepped for (peri)menopause drops in bone density. But, with dietary shift and the anti cancer sun issues, I think old people in general need to talk to their GP about it.
The SAD thing, and MS also come up. I think the SAD one is covered by your mood disorder and the need for context. I didn't see MS well covered?
The SAD thing, and MS also come up. I think the SAD one is covered by your mood disorder and the need for context. I didn't see MS well covered?
Thanks, George. I’m a new Australian (U.S. transplant) and still getting up to speed on the local medical culture. But, re: SAD/mood, bright-light therapy is first-line; I treat vitamin D as “correct deficiency, don’t expect it to replace standard care.”
On MS (the bit I didn’t cover well): Higher lifelong 25(OH)D is linked to lower MS risk (observational + genetic lines point the same way). In people already diagnosed, adding high-dose D3 to disease-modifying therapy hasn’t reliably cut relapses; MRI signals are mixed.
So, test and correct deficiency (good general health practice), but don’t expect vitamin D to function as a disease-modifying add-on.
On MS (the bit I didn’t cover well): Higher lifelong 25(OH)D is linked to lower MS risk (observational + genetic lines point the same way). In people already diagnosed, adding high-dose D3 to disease-modifying therapy hasn’t reliably cut relapses; MRI signals are mixed.
So, test and correct deficiency (good general health practice), but don’t expect vitamin D to function as a disease-modifying add-on.
Bryan Johnson wishes
70/100 (Strong, with nuance) 68/100 (Moderate-to-Strong)
I would argue the ratio of 70/100 to 68/100 is 1.02 (or 0.97 if you prefer) and this is a distinction without meaning.