alt Hacker NewsI read the summary thoroughly and scanned the rest, and I don’t think the paper supports the grandparent comment.
The paper says you can produce enough vitamin d to maintain healthy levels from a specific amount of sunlight per day, depending on latitude and skin color.
The original comment suggests that there’s some (very short!) limit beyond which the body is unable to produce more vitamin d, which is very different. I’d be very curious to see sources for that.
Ah, I didn't read their comment too strictly.
UVB synthesizes cholecalciferol (vitamin D3) in the skin, which the liver converts into calcifediol (what blood tests usually measure), which the kidneys convert to calcitriol (the active hormone). Wiki claims the kidneys have a negative feedback loop, converting excess calcifediol into inactive 24,25-dihydroxycholecalciferol. I wish I had better sources (for my vitamin D pdf folder).
https://en.wikipedia.org/wiki/Vitamin_D#Excess
But just knowing that, I don't immediately see anything limiting cholecalciferol or calcifediol amount and storage.