Vitamin A and Colestipol: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Vitamin A
Colestipol
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.
What happens
Decreased vitamin A effectiveness
Interaction Deep Dive
Although colestipol may interfere with absorption of fat soluble vitamins, several studies have demonstrated only minor decreases in vitamin A and vitamin E concentrations during colestipol therapy2341.
Why it happens (mechanism)
Decreased vitamin A absorption
Literature reports
1 report — tap to read
a) In 22 children ranging in age from 5 to 17 years, serum vitamin A and vitamin E concentrations decreased, but not to levels associated with deficiency, after therapy with 15 to 20 g/day of colestipol 1.
Common questions
Can I take Vitamin A and Colestipol together?
Decreased vitamin A effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Vitamin A and Colestipol 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 "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Vitamin A or Colestipol 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 (4)
- Anon: Colestipol therapy and selected vitamin and mineral levels in children. Nutr Rev 1980; 38:236-237.
- Schlierf G, Vogel G, Kohlmeier M, et al: Long-term therapy of familial hypercholesterolemia in young patients with colestipol: availability of minerals and vitamins. Klin Wochenschr 1985; 63:802-806.
- Probstfield JL, Lin TL, Peters J, et al: Carotenoids and vitamin A: the effect of hypochloesterolemic agents on serum levels. Metabolism 1985; 34:88-91.
- Schwarz KB, Goldstein PD, Witztum JL, et al: Fat-soluble vitamin concentrations in hypercholesterolemic children trated with colestipol. Pediatrics 1980; 65:243-250.
Keep reading about Colestipol
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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