你也不贴个出处，不严谨。哈佛医学院说的是：“between 40 and 60 ng/mL”

“At that time, their experts concluded: "Based on all the evidence, at a minimum, we recommend vitamin D levels of 30 ng/mL, and because of the vagaries of some of the assays, to guarantee sufficiency, we recommend between 40 and 60 ng/mL for both children and adults.”

链接