@DanCraig808 Have you read through this thread? One very knowledgeable person about B2 is PhD Biochemist Greg Russell-Jones, who runs/is affiliated with the B-12 Oils company. He says that without enough functional B2, ythe body doesn't recycle folate and , I believe B12. Having enough functional B2 requires adequate thyroid function and perhaps a bit of iodine, adequate selenium, and enough molybdenum.
It sounds easy enough, but for those of us who have reached this point, that is of developing deficiencies over decades, ramping up can take time and patience. I'm talking months here. Maybe for each one. I titrated up largely on BodyBio drops, which can be taken drop by drop. In the case of molybdenum, I started with a drop in a quarter of a cup of water and took a teaspoon or so so of that.
You get the picture. I've worked on B2 levels for a couple of years now, and after adding L-carnitine to my supplements, find that I am adding some of the sublingual back in, experimenting to see if levels shift everything else I've got going. As others have pointed out, these vitamins are interdependent, each one supports how the others get used...
Over two years ago, a fraction of a sublingual B12 gave me heart irregularities that put me in the emergency room. Now I use two or three squirts a day of the oil. But for me, there are still challenges!