CYP24A1 and memory impairment: Variations in the CYP24A1 gene lead to an accumulation of vitamin D3 and an associated hypervitaminosis D phenotype (Griffin et al., 2020), Hypervitaminosis D is linked to a range of severe health hazards, including reduced appetite, constipation, depressive symptoms, and memory impairment—similar issues experienced by individuals with chronic opioid use (Nelson and Camilleri, 2015).