Hi AL,
Resveratrol is a natural supplement made from red grapes. It is also a hemoglobin inducer that can be used with wheatgrass. Hydroxyurea is a drug that is also a hemoglobin inducer and it can be taken with the other supplements. However, it is a drug, and must be taken under a doctor's supervision.
I am certain the spots were a reaction to the unfiltered blood. Often, an antihistamine like benadryl, is taken along with the transfusion to minimize this type of reaction.