Q: Could taking psyllium powder interfere with my absorption of other nutrients?
A: The effect of standard doses of psyllium on vitamin and mineral absorption from a subsequent meal is minimal. People typically take psyllium for its mild laxative effect or as a fiber supplement that helps lower cholesterol or blood sugar.
It’s well known that large amounts of fiber can interfere with the absorption of some nutrients, especially certain minerals. But research has found that a standard psyllium dose (usually a teaspoon, with about 4 grams of mostly soluble fiber) taken immediately before mealtime has little or no effect on vitamins or minerals.
In general, any small effect that moderate amounts of fiber—from food or a supplement—may have on nutrient absorption is not a worry, especially if your intake of nutrients is adequate. It is better, however, to get fiber from food than from a powder or pills, since fiber-rich foods are very nutritious.
Note: Psyllium may interfere with some prescription drugs, so talk to your doctor or pharmacist if you take psyllium and a drug at the same time. Labels on psyllium usually say to take it at least two hours before or after medications.
Also see The Power of Psyllium Fiber.