Drug Interaction Report

Ascorbic Acid (Vitamin C) and Aluminum Phosphate: Interaction Details

Name: Ascorbic Acid (Vitamin C) and Aluminum Phosphate Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Ascorbic Acid (Vitamin C) and Aluminum Phosphate interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Ascorbic Acid (Vitamin C)

C-500® Chewable Tablet C-Time® Cecon® Drops Centrum® Singles-Vitamin C Cevi-Bid® Halls Defense® Sunkist® Vitamin C

Aluminum Phosphate

No brand names on record

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Minor

Usually limited clinical impact.

Minor

Moderate

Major

Contraindicated

How we grade severity & evidence

Severity levels

Contraindicated: These should generally not be used together.
Major: Potentially serious — often needs a change or close monitoring.
Moderate: Can be significant — usually manageable with monitoring.
Minor: Usually limited clinical impact.

Evidence grades

Established: Well documented — supported by controlled studies or strong clinical data.
Probable: Good supporting evidence, though not definitively proven.
Suspected: Some evidence suggests this interaction, but it is not well established.
Possible: Limited or conflicting evidence; the interaction may occur.
Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 22 documented Ascorbic Acid (Vitamin C) interactions, 7 are rated minor — including this one.

Onset

delayed

Evidence

theoretical

Severity

Minor

What happens

Aluminum toxicity (personality changes, seizures, coma)

Interaction Deep Dive

Concomitant aluminum antacids with ascorbic acid 2 grams three times daily has been reported to increase urinary aluminum elimination, suggesting increased aluminum absorption¹.

Why it happens (mechanism)

Increased aluminum absorption

Common questions

Can I take Ascorbic Acid (Vitamin C) and Aluminum Phosphate together?

Aluminum toxicity (personality changes, seizures, coma) Always confirm with your pharmacist or prescriber before making any change.

How serious is the Ascorbic Acid (Vitamin C) and Aluminum Phosphate interaction?

It is rated minor. Usually limited clinical impact.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

Does my dose of Ascorbic Acid (Vitamin C) or Aluminum Phosphate need adjusting while I take them together?
What symptoms should prompt me to call you or my prescriber right away?
Does the timing of my doses matter for this combination?
Is there anything you'd monitor while I'm on both?

References (1)

Domingo JL, Gomez M, Llobet JM, et al: Effect of ascorbic acid on gastrointestinal aluminum absorption (letter). Lancet 1991; 338:1467.

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If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

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