When vitamin C is added to wheat-soy porridge that has already had phytic acid removed, more iron is absorbed by the body compared to porridge without vitamin C, but the increase is smaller than the...

Pro

Against

Mechanism

Synthesis from 1 study

How it works

Even after removing the substance that binds iron and blocks absorption, most iron is still in a form the gut can't easily take up. Vitamin C changes that iron into a different form that the gut can grab and send into the blood, so more of it gets absorbed. This boost is smaller than removing the...

Most probable mechanism

In Simple Terms

Vitamin C keeps iron in a form that the gut can easily absorb, even after other blockers are removed. It helps turn iron into a charged particle that fits into a special gate in the gut lining, letting more iron into the bloodstream.

Causal chain

Dietary non-heme iron in the intestinal lumen exists primarily in the oxidized ferric (Fe³⁺) state, which has low solubility and poor affinity for the iron transporter DMT1.

Verified by multiple studies

which leads to

Ascorbic acid acts as a reducing agent, converting ferric iron (Fe³⁺) to the ferrous state (Fe²⁺), which is more soluble and has higher affinity for the divalent metal transporter 1 (DMT1) on the apical membrane of duodenal enterocytes.

Verified by multiple studies

which leads to

Ferrous iron (Fe²⁺) binds to DMT1 and is transported across the apical membrane into the enterocyte, where it enters systemic circulation via ferroportin.

Verified by multiple studies

which leads to

Removal of phytic acid eliminates its chelation of iron, freeing iron ions to be reduced and transported, but without ascorbic acid, a portion remains in the less absorbable ferric form; ascorbic acid ensures maximal conversion to the ferrous state, further increasing uptake.

Verified by multiple studies

Evidence from Studies

Supporting (1)

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Degradation of phytic acid in cereal porridges improves iron absorption by human subjects.

Randomized Controlled Trial

Human

2003 May

Contradicting (0)

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No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Degradation of phytic acid in cereal porridges improves iron absorption by human subjects.

Score: 48

DOI: 10.1093/AJCN/77.5.1213

Similar Assertions

Adding milk to cereal porridge that has been treated to remove phytic acid reduces the amount of iron the body can absorb, even when vitamin C is present.

77%

Removing phytic acid from cereal porridges made with water improves how much iron the body absorbs from these meals, with absorption rates increasing significantly in both wheat and maize porridges.

71%

Removing phytic acid from sorghum porridge usually improves iron absorption, but this benefit does not occur when the sorghum has high levels of tannins. In sorghum with low tannins, the improvement in iron absorption still happens.

70%