POTENTIAL interactions between medications are considered before prescribing, but how drugs and nutrients interact is not as well studied. Assessing the effects of poly-pharmacy is particularly relevant for older patients or those requiring several medications and supplements.
Drug Effects on nutrients
Altering food intake
Increasing or decreasing appetite, causing nausea, constipation and/or dry mouth.
Altering nutrient absorption
Drugs may inhibit the absorption of nutrients by competing with the same absorption mechanism (e.g. carbamazepine competitively inhibits the absorption of biotin).2-4
Altering nutrient metabolism
Some drugs will alter nutrient requirements by increasing their metabolism (e.g. phenytoin increases the metabolism of, and hence requirements for, vitamins D5, K6 and folate).7
Altering excretion of nutrients