How Much Do We Need?

[jessencraigs]

The current recommended intake of vitamin D is 200 IUs (international units) for those up to age 50; 400 IUs for people 51-70; and 600 IUs for those older than 70. Requirements increase with age because older skin produces less vitamin D.

But these recommendations date back to 1997. "Additional studies have been published since that time documenting the effectiveness of higher levels of vitamin D," says Holick, who was a member of the Institute of Medicine (IOM) committee that issued the recommendations.

[BellaVega]

How much vitamin D does one get from 30-minutes exposure to the sun? I realize in the winter that one doesn't get as much sun exposure and so one needs to supplement it with vitamins. But is 30-minute exposure sufficient for one's daily intake of vitamin D?