<prompt> Which antibiotic decreases absorption of iron ?SulfonamideTetracyclinesErythromycinCiprofloxacin  <response>: Ans. is b i.e., Tetracycline Factors facilitating iron absorption - Acid, ascorbic acid Vit C, amino acids containing SH radical, meat. All these are reducing substances which enhance conversion of Fe to Fe and thus improve absorption. Factors impending iron absorption - antacids, alkalies, phosphate rich in egg yolk, phytates in maize, wheat, tetracyclines, presence of other food in stomach. 