sentences:  GULO is required for converting glucose to ascorbic acid (vitamin C), which is needed to repair arteries; following the loss of GULO, those primates who adopted diets less abundant in vitamin C may have used Lp(a) as an ascorbic-acid surrogate to repair arterial walls.The half-life of Lp(a) in circulation is approximately three to four days.The mechanism and sites of Lp(a) catabolism are largely unknown.