Even mainstream medicine is now actively promoting Vit D for immune system benefits. Recommended dose for all adults is often 1,000 IU, instead of the old standard 400 IU.
Post “change” women are higher.
Seems to be some solid evidence out there now.
I take 4000 to 6000 a day. Your body uses about 4000 I.U. a day. I’ve been taking 4-6000 I.U. a day for several years, except in the summer, I drop it to around 2000 a day then. Just to maintain a decent D blood level. It’s very hard to OD on D.