AFM and hyperinsulinemic hypoglycemia, familial, 4: Different aspects were studied: circulating levels of zinc [39,40,41], copper [39,40,41], vitamin D [32,33,40,42], selenium [43], vitamin K1 [41], vitamin E, and Afamin (vitamin E-binding protein) [44]; deficiency of vitamin D [33,40,42,45] or vitamin B12 [40]; and supplementation of vitamin D [40,42] or magnesium [38].