Excellent source for Vitamin D information is
www.vitamindcouncil.org
I don't agree with Cannell on everything (when have I ever agreed with anything completely?
) I'm a bane to my physicians.
He believes that A and D are antagonistic - I'm not so sure - or if so, maybe they need to be taken at different times in the day.... like iron and most other vitamins/minerals.
That said, he's got a lot of good information...
alys