Based on its name alone, I'd guess that vital wheat gluten is pretty darn important; integral, essential, perhaps even crucial.
To be sure though, I
googled it. Basically, it's powdered gluten. According to
King Arthur Flour, it "provides the extra gluten that whole-grain loaves need to rise their highest. It's particularly helpful with loaves that have low-gluten whole grain flours, such as rye, oat, teff, spelt, or buckwheat."
Hope this helps,
--Rich
I don't know what you think about dinner, but there must be a relation between the breakfast and the happiness. --Cemal Süreyya