IL1B and hyperinsulinemic hypoglycemia, familial, 4: To determine whether supplementation of exogenous 1,25(OH)2D3 can prevent knee OA caused by 1,25(OH)2D deficiency, we performed in vivo supplementation of exogenous 1,25(OH)2D3 in 1α(OH)ase-/- mice and in vitro treatment of 1,25(OH)2D3 in 2D or 3D cultures of human articular chondrocytes with IL-1β induction.