Hi Barbara - You probably noticed from my posts that I am also vegetarian except for occasional fish and am also dairy free. My ferritin, while not high, is within normal range (92 ug/L a week ago). My iron is normal too (26 umol/L) as are B12 and folate. (I don't supplement except for Vit. D3). I don't think your husband's ferritin can be connected to diet unless he is not ingesting enough foods which enhance iron absorption or is perhaps eating/drinking things that prevent iron absorption.
You may have already checked all this out. If not, here's a useful and easy to read website that might help:
http://www.nomeatathlete.com/iron-for-vegetarians/
I am having an IgG infusion tomorrow as my globulins have dropped back below normal again.