Of Interest: Is Sunscreen the New Margarine?

[Paulbfast]

You actually will reach a maximum amount of vitamin D production in response to the sun well before any kind of burning or addition of supplemental levels of UV. More UV than you need will just turn the vitamin D precursors into a couple of sterol analog products instead of vitamin D. It will not increase vitamin D levels. It is another way of preventing the system from accumulating excess vitamin D in response to UV exposure.

Vitamin D: Production, Metabolism, and Mechanisms of Action - Endotext - NCBI Bookshelf

I understand that the system will regulate the vitamin D response and as such is "safer" than supplementation.

The real gem for us is in your link.

"Skeletal muscle.

Proximal muscle weakness is a hallmark of vitamin D deficiency, and reduced high energy substrates (ATP, creatinine phosphate) have been observed in that condition (445). Myoblasts contain VDR, although the expression of VDR in mature muscle cells is controversial. Muscle weakness may reflect the lower levels of calcium and phosphate rather than a reduction in 1,25(OH)2D. However, evidence for a direct role of 1,25(OH)2D and VDR in muscle function is increasing (446). Moreover, 1,25(OH)2D may have actions on muscle that do not require the VDR, at least the genomic functons of VDR. The Boland laboratory (447) has demonstrated acute effects of 1,25(OH)2D on calcium uptake, PLC, PLA2, PLD, PKC, and adenylate cyclase activities, all of which may alter muscle function."

What I have been looking for is if there is a pathway between vitamin D and ATP? Or perhaps some other "connection"? It is alluded to but does it actually exist?

The second best part - my old and growing prostate is thankful!

[凤凰来仪]

I don't know exactly what preexisting medical condition you have that is causing you to be so abnormally deficient in Vitamin D or how you think you are overcoming the negative feedback loops associated with UV induced vitamin D production. Must be a pretty severe medical condition if you are frequently checking serum levels.

Very puzzling.

[Paulbfast]

I don't know exactly what preexisting medical condition you have that is causing you to be so abnormally deficient in Vitamin D or how you think you are overcoming the negative feedback loops associated with UV induced vitamin D production. Must be a pretty severe medical condition if you are frequently checking serum levels.

I don't recall saying I was "abnormally deficient" in vitamin D? I have found most of the "negative feedback" I receive comes from here!

It reminds me of something I read written in jest:

I run my experiments.
I skip controls.
And I jump to conclusion.

I participate in a vitamin D research project. I send them blood and they check my vitamin D level.

In the famous words of King Kamehameha - Aloha!