I never really paid attention to the difference, until I realized that Folinic Acid is in IntrinsiB12/Folate by Solgar, and yes, the IntrinsiB12 seems to work magic for some people. I was thinking at first it was the Intrinsic Factor in it.....but now I"m wondering if it is the *folinic* acid, which is a different form of bio-available folate (my understanding) vs 5-MTHF which is Metafolin. Furthermore, I started reading some reviews on iherb.com, and some people are reporting, for the Folate supplements that include folinic acid, that for some reason, it's the only folate they've tried that has made a difference in their anemia, or in how they feel. It is making me think that some of us really need it. Looking back, I felt better on Rich's Simplified Protocol than on Metafolin combined with some other B forms and all three B12 forms, and I think the addition of the folinic acid in the IntrinsiB12/Folate by Solgar (in Rich's protocol) is why. Thoughts? I am going to order the Source Naturals Folinic Acid on its own and see how that works. When something helps me, I can tell, like with the IntrinsiB12/Folate. I am going to keep taking my Metafolin, of course, but I'm hoping to see a boost from this new form, on it's own.