Which dietary constituent produces the greatest enhancement of non-haem (inorganic) iron absorption from a single meal?
- A Tea polyphenols (tannins)
- B Calcium supplements
- C Ascorbic acid ✓
- D Phytates from whole grain cereals
Correct answer: C. Ascorbic acid
Explanation
Ascorbic acid is the most potent enhancer of non-haem iron absorption. It reduces ferric iron (Fe3+) to ferrous iron (Fe2+), the only form accepted by DMT1 in the duodenal brush border, and it forms a soluble chelate that keeps iron absorbable at the alkaline pH of the duodenum. Options A and D are inhibitors: tannins and phytates bind iron and reduce its uptake. Calcium also impairs haem and non-haem iron absorption when taken together.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.