[layman51]

Does anyone know whether UVA or UVB is more conducive to producing vitamin D naturally? A quick search shows me that it is mainly UVB that's responsible for that, but unfortunately, this is what gets blocked out by glass windows and sunscreen. On the other hand, UVA is what causes early aging.

So this is just an unfortunate situation because I don't think there's a way of just getting UVB into you in a safe way.

[jodrellblank]

UVB makes it.

UBA denatures it[1], which I thought was how we avoid overdose levels building up in the skin when outside, but can't find a source for that.

Suggested as a reason why fair-skinned indoor workers are getting more melanomas, (ref glass blocking UVB and passing UVA): https://www.sciencedirect.com/science/article/abs/pii/S03069...

[picofarad]

Offhand, what was the overdose level? Because 150ng/ml (adjust if I messed units up) isnt an overdose and most people are around ~50 unless they supplement (I mean people outside the 25th parallel.) I think even approaching 300ng/ml is possibly safe as long as you're accounting for the calcium.

I aim to be around 105ng/ml.

[jodrellblank]

I have no idea what the numbers were, I took it in as a system idea: more time in sunlight, more UVB, more Vitamin D. Then UVA breaks it down slowly, so more builds up in the skin, more is being broken down, acting as a control-feedback brake on the increase.

> "unless they supplement"

I have seen plenty of claims that low levels of Vitamin D correlate with many diseases and overall mortality, but that supplementing Vitamin D hasn't been proven to help. Is there any consensus on that?

> "as long as you're accounting for the calcium".

Vitamin D helps bodies absorb calcium but has concerns about high blood levels of calcium. Taking Vitamin K2 as well helps redirect that calcium to the bones instead of the artery walls, apparently. But high levels of Vitamin A could also be causing loss of bone calcium into the blood:

"""in the industrialized world excess of vitamin A has been suggested to be a risk factor for secondary osteoporosis and enhanced susceptibility to fractures. Preclinical studies unequivocally have shown that increased amounts of vitamin A cause decreased cortical bone mass and weaker bones due to enhanced periosteal bone resorption. Initial clinical studies demonstrated a negative association between intake of vitamin A, as well as serum levels of vitamin A, and bone mass and fracture susceptibility. In some studies, these observations have been confirmed, but in other studies no such associations have been observed. One meta-analysis found that both low and high serum levels of vitamin A were associated with increased relative risk of hip fractures.""" - https://pmc.ncbi.nlm.nih.gov/articles/PMC11070503/

which could be a confounding factor with Vitamin A and its precursors in so many animal and plant foods and fortified into more, and in daily multivitamin supplements, skin creams, moisturisers and such.

[genewitch]

> Is there any consensus on that?

I'm not sure. there's two doctors that i based my supplementation of D3+K2 on, but i cannot remember their names or link the videos. The assertion made was that blood serum 25OH Dwhatever of 100ng/ml (or dl, i always forget, but the one that makes sense) is enough to prevent most disease, like colds, flu, etc.

Another interesting thing vis a vis overdose/excess D3 is that for covid there was a hospital protocol for 50,000 IU given three times to "knock covid out"

I never read a study, sorry, so i can't link.

I started on this path because my wife got cancer and afterward was getting sick and always tired, d3 serum test was 28ng/ml so we brought her up to 100ng/ml and she hasn't been "sick" in 5 years. Additionally she no longer has to supplement calcium, which her oncologist said she'd have to do the rest of her life.

I buy "Micro Ingredients Vitamin D3 10,000 IU + K2 MK-7 200 mcg, 600 Softgels with Virgin Coconut Oil (2 Pack)" - B0D7B94P8D, and have for years. consistently good, and the blood tests prove it's real. Not affiliated.

I supplement a lot of stuff because my diet sucks and it's something i have been working on this year.

[krupan]

The article explains that it is much safer than not getting UVB. Nothing in this universe is completely safe, but the evidence is that getting UVB is bar far safer than not getting it