<prompt> All of the following are the reasons for impaired absorption of calcium except:Inositol hexaphosphate in cerealsHigh intake of oxalateHigh concentrations of fatty acids in the intestinal lumenDecreased iron intake  <response>: Phytic acid inositol hexaphosphate in cereals binds calcium in the intestinal lumen, preventing its absorption. Other minerals, including zinc, are also chelated by phytate. This is mainly a problem among people who consume large amounts of unleavened whole-wheat products; yeast contains an enzyme, phytase, that dephosphorylates phytate, so rendering it inactive. High concentrations of fatty acids in the intestinal lumen, as a result of impaired fat absorption, can also reduce calcium absorption by forming insoluble calcium salts; a high intake of oxalate can sometimes cause deficiency since calcium oxalate is insoluble.HARPERS ILLUSTRATED BIOCHEMISTRY30th, Page No: 541 