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Does High-fiber foods Affect Vitamin B1?
May affect absorption or how you feel
The short answer
Accelerated GI transit from high fiber reduces contact time for thiamine absorption in the small intestine.
How to arrange timing
Take thiamine at least 1 hour apart from high-fiber meals.
Reference
Reference noted for this food and supplement combination: NIH ODS 2024
Important context
The effect can also change with food amount, supplement dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.