hiya to all the ladies, :)
have to say, im sure sickness abates after each baby...maybe the body accepts whats happening better ....with practice??
but sickness was horrendous with first....!
I did find (with experience) that you really do have to keep your belly more or less full, as sickness always creeps in on an empty / half empty stomach !!
bit difficult when you cant keep anything down..
although I never seemed to have a problem keeping peanut m&ms and revels, and other mini munchie bad foods down!! 
and JJKM I too never took my iron through fear of it making my sickness worse....and with some babies I was so tired all the time....
but with the twins...I collapsed from exhaustion, and had to be put on oxygen in hospital for 2 days ...so whilst in hosp. they MADE me take iron..and it actually didnt affect the nausea at all, and I made a huge improvement energy wise (still shattered....but at least I could have energy to breath & get upstairs occasionally !!)
maybe if your past the 16 weeks, and always take lots of food (NOT dairy, coffee, tea etc things that interfere with iron absorbtion) but do eat lots beforehand, this should help...as it advises to take on an empty stomach so it will absorb better...but if this stops you from taking it because it then makes you sick....surely its better to get some iron by taking with food?