Prescription and non-prescription medications can affect a person’s nutritional status by several mechanisms. Drugs can increase and decrease appetite, alter the absorption of nutrients in the intestine, affect how nutrients are used within the body, and increase the excretion of nutrients. Medications also can alter the amount and site of nutrient storage within the body. For example, oral contraceptives affect the distribution of vitamin B12 in the tissues.
Take vitamin B6 for an example. This vitamin functions as a co-enzyme in several metabolic reactions that involve the breakdown, build-up, and alteration of proteins and their components, the amino acids. Any drug that contains one or more amino acids might potentially bind to vitamin B6 and inhibit its function. Several categories of drugs interfere with vitamin B6. A drug-induced vitamin B6 deficiency does not produce obvious symptoms; however, physiological and psychological changes can develop when this nutrient is at marginal levels, including an increased risk for cardiovascular disease, irregular sleep habits, anemia, irritability, lethargy, and a reduced ability to handle stress.
Prescription and non-prescription medications often aggravate a pre-existing nutrient deficiency. Chronic poor dietary intake or malabsorption of dietary nutrients can produce deficiencies that often go unnoticed, especially in seniors. A medication that interferes with nutrient status only aggravates subtle deficiencies. For example, many medications commonly used by women of childbearing age, including aspirin and oral contraceptives, alter folic acid metabolism and could aggravate an already compromised folate status. Other minerals marginally supplied in women’s diets, such as calcium, iron, magnesium, and zinc, are further depleted by taking common prescription drugs, such as tetracycline, neomycin, alcohol, aspirin, and primadone.
The extent that a drug influences a person’s nutritional state depends on: 1) the body’s nutrient reserves prior to and during medication therapy; 2) age, size, and medical condition; 3) individual variations in absorption and excretion of nutrients; 4) the adequacy of dietary intake; and 5) the amount and duration of drug therapy.
More attention by the medical community must be given to these potentially serious interactions, especially in seniors who may be taking one or more medications for long periods of time, who typically consume suboptimal diets, and who are prone to reduced absorption of and increased requirements for nutrients. Photo credit: Chuck Olsen via Compfight