That could be done on a separate thread, could it not? If she trusts her vet to do know what is best for her horse, then that is all that matters, right? :)
ETA: Not trying to say you were out to offend anyone, just saying that it was off topic, and it had already been addressed before.
The best thing about this Forum is that it allows for (polite) open debate and sometimes going slightly off thread can open up new ideas that have a bearing on the original thread
The lady asked about how she could streamline her supplements and sometimes the best way to do this is to consider why you're feeding them and if you need them. For instance she is feeding a Safe Choice product, I use Safe Choice Life Design Senior Horse Feed myself for two of my horses and as her horse is 19 then I'm thinking this might be the one she is also using. If you look at the list of ingredients in it then you will see that it already contains Rice Bran, Flax seed and Omega 3 & 6 fatty acids in quite high levels and states that it has increased fat levels which is why I question the need for the Flax seed oil
It also contains Calcium, phosphorus, copper, zinc, selenium & Vitamins C,A,D3 & E
If you check on the Red Cell ingredients you will see that some of these things are also in that which could mean you are overloading your horses system with them which isn't a good thing to do.
The vet should be able to supply a straight iron and B12 supplement, I know that my one can.
Without wishing to upset anyone by going 'off thread' again As far as the worm situation goes as well as addressing the burden in the horses on the yard the source of the problem should also be addressed. If the grazing is now so badly contaminated that the horses are reinfesting so quickly as to lose weight in just a few days then the whole land management system there needs to be reviewed.