From the Guidelines
Taking 80 mg of vitamin C with iron supplements is recommended to improve iron absorption for patients with iron deficiency anemia. This dose of vitamin C has been shown to enhance iron absorption by forming a chelate with iron and reducing ferric to ferrous iron, as suggested by a recent iron isotope study 1. While evidence supporting vitamin C administration to improve iron absorption is mixed, this specific dose has been identified as beneficial. It is essential to take vitamin C at the same time as iron supplements, and on an empty stomach, to maximize absorption.
Some key points to consider when taking iron supplements with vitamin C include:
- Avoid consuming tea and coffee within an hour after taking iron, as they can inhibit iron absorption 1
- Do not take iron more than once a day, as this can increase side effects without improving absorption 1
- Ferrous iron salts, such as ferrous sulfate, ferrous fumarate, and ferrous gluconate, are reasonable choices for oral iron supplementation due to their low cost and comparable effectiveness to other products 1
Overall, taking 80 mg of vitamin C with iron supplements can help improve iron absorption and support the management of iron deficiency anemia, as indicated by recent clinical practice updates 1.
From the Research
Vitamin C Dosage with Iron Supplements for Anemia
- The ideal dose of vitamin C to take with iron supplements for iron deficiency anemia is not clearly established, as the evidence is limited and inconclusive 2.
- A study published in 2020 suggests that providing morning doses of 60-120 mg iron as a ferrous salt given with ascorbic acid on alternate days may be an optimal oral dosing regimen for women with iron-deficiency and mild IDA 3.
- Another study from 2020 found that oral iron supplements alone were equivalent to oral iron supplements plus vitamin C in improving hemoglobin recovery and iron absorption in patients with IDA, with a dose of 200 mg of vitamin C per day 4.
- Vitamin C may have a dual action in iron supplement therapeutics, not only increasing absorbable ferrous iron but also preventing liver damage induced by iron overload 5.
- The response to iron supplementation in iron-deficiency anemia can vary depending on the underlying cause of anemia, with some studies suggesting that a ≥1.0-g/dL increase in hemoglobin at day 14 of oral iron may be a useful predictor of satisfactory overall hemoglobin response 6.
Key Findings
- The evidence suggests that vitamin C may enhance iron absorption, but the optimal dose and frequency of administration are unclear 2, 3.
- Some studies suggest that vitamin C may not be essential for patients with IDA, and that oral iron supplements alone may be sufficient 4.
- Vitamin C may have additional benefits in preventing liver damage induced by iron overload, but more research is needed to confirm this 5.
- The response to iron supplementation can vary depending on the underlying cause of anemia, and individualized treatment approaches may be necessary 6.