Answer
Yes. Prolonged treatment can reduce absorption of fat-soluble vitamins, particularly vitamins A, D and K, and may also affect folate.
Sources for this answer
- Colestyramine 4 g Powder for Oral Suspension — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.