Hormones can affect many nutrients:

Here is a list:
http://www.chiro.org/nutrition/ABSTR...ceptives.shtml

With no gall bladder your fat intake has to be spaced out and not in huge meals. But you should be able to tolerate some fats. You should still be making bile, only not storing it. If your bile seems sluggish or you still get "symptoms" with many foods...try using a gram a day of Taurine. This amino acid grabs onto the cholesterol in the bile, and helps it move out better.

Your Welchol only grabs the bile AFTER the bile exits the duct.
The taurine helps at the liver level.

I'd take the nutrients in between the Welchol and not with it.

Also check your magnesium...if it is oxide it is not being absorbed (it remains in the bowel which with the constipating Welcol may be necessary for you at times). Get another type, either SlowMag or a chelated form for systemic absorption.
You can also get rub on lotion now, the new Morton Epsom Lotion, this bypasses the GI tract entirely and is absorbed thru the skin. Many of us find it very helpful for neuropathy pain.

WalMart, Walgreen's and online at Amazon are the most common places to find it. Not all stores carry it locally.