The research does support the use of vitamin D3 as another way to bolster our immune system against the flu.
The new adult dosage recommended is 2000 iu. per day and I think that half that for children would be good.
There is a website by the Vitamin D Research group that can give you all the updated info on Vitamin D3.
I was also reading about the elserberry extract being effective against the H1N1 strain. I will post more on that later.