Which antibiotic decreases absorption of iron ?

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.