Is there any case law where a defendant's medical condition can be proven to justify the quantity of marijuana in his possession?

Defendant seems to suggest that, had he been able to testify to his medical condition and shown the photos demonstrating this condition, it would have tended to justify the quantity of marijuana in his possession. But how would a jury determine the amount of marijuana required to treat a particular condition, at least without the testimony of a knowledgeable physician? There is no suggestion defendant was qualified to testify to the relationship between his condition and the quantity of marijuana necessary to treat it. And there is no indication defendant intended to call an expert to provide this evidence; this was not the subject of the motion in limine. As the Attorney General points out, the trial court's determination whether certain evidence is relevant is reviewed under an abuse of discretion standard. (People v. Jablonski (2006) 37 Cal.4th 774, 821.) We fail to discern an abuse of discretion.