Which vitamin enhances the absorption of iron?

Question

BlackTom AI · Accepted Answer

Vitamin C reduces ferric iron (Fe3+) to the more soluble ferrous form (Fe2+), which is key to increasing intestinal absorption of non‑heme iron.

1. Relevant knowledge points and concepts
- Two major dietary iron forms: heme (from animal sources) and non‑heme (from plant sources). Non‑heme iron is less readily absorbed. 
- Iron must be in the ferrous (Fe2+) state for optimal uptake across the duodenal enterocyte apical membrane via divalent metal transporter 1 (DMT1). 
- Vitamin C (ascorbic acid) is a reducing agent and a chelator; it converts Fe3+ → Fe2+ and forms soluble iron‑ascorbate complexes, protecting iron from inhibitors (phytates, polyphenols) and gastric pH effects.

2. Step‑by‑step reasoning
- Dietary non‑heme iron often exists as Fe3+, which is poorly soluble at intestinal pH and binds inhibitors. 
- Ascorbic acid donates electrons to Fe3+, producing Fe2+: Fe3+ + e‑ → Fe2+. This increases solubility.
- Vitamin C also forms a chelate with iron that remains soluble and accessible to DMT1 for transport into enterocytes.
- Therefore, co‑ingestion of vitamin C with plant iron sources markedly raises fractional iron absorption.

3. Intermediate steps / illustrative chemical transformation
- Fe3+ (insoluble) + ascorbate (reducing agent) → Fe2+ (soluble) + dehydroascorbate.
- Soluble Fe2+ + DMT1 → transported into enterocyte → contributes to body iron pool.

4. Why the correct answer is correct
- Because vitamin C both chemically reduces iron to the absorbable Fe2+ state and forms soluble complexes that overcome dietary inhibitors, it directly and reproducibly enhances iron absorption.

5. Why the other options are incorrect
- Vitamin D: promotes calcium/phosphate homeostasis and bone health, not iron absorption. 
- Vitamin B‑12: required for DNA synthesis and red blood cell maturation but does not enhance iron uptake. 
- Calcium: can inhibit iron absorption by competing with iron for uptake and forming insoluble complexes.

6. Conclusion
This explanation confirms the correct answer is vitamin C, matching the provided answer.

Which vitamin enhances the absorption of iron?单项选择题

类似问题

Iron absorption in humans is facilitated by the presence of:

Which provides the most absorbable iron?

Which of the following factors can enhance intestinal iron absorption?

Iron absorption is impaired by:

Which of the following increases the absorption of iron?

Comprehension-Level Multiple-Choice Items Which of the following impairs iron absorption?

Comprehension-Level Multiple-Choice Items A zinc toxicity reduces ____.

Which of the following does not inhibit the body’s absorption of iron?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单