I saw something on the HIH website about latitudes and adequate sunlight for making vitamin D.
IIRC, north of Boston there is inadequate sunlight from November through February for the making of any vitamin D. South of somewhere in South Carolina there is always adequate sunlight.
That may be true, but also consider the age of the person too. AS you age your body doesn’t do things as efficiently as it used to, so it sure doesn’t hurt to augment your body’s production of anything that helps the immune system.
General rule is that most people are deficient in vitamins, rather than having normal or surplus levels of them.
that’s interesting info
probably here in Indiana similar
I try to be outside 45 mins daily
my dog loves to walk no matter if cold, hot, wet, frozen or whatever
If you get outdoors enough every day and do not use sunscreen. Otherwise, even in a sunny climate, one is prone to low vitamin D levels.