Drug Interactions with Nutrients

By Carol Ann Rinzler

Like some foods, individual nutrients — vitamins and minerals — may also interact with medicines. The table lists some common vitamin/mineral and drug interactions. Here are four common examples:

  • Antacids containing aluminum compounds bind with the bone-building mineral phosphorous, carrying it right out of your body.
  • Antiulcer drugs cimetidine (Tagamet) and ranitidine (Zantac) can make you positively giddy. These drugs reduce stomach acidity, which means the body absorbs alcohol more efficiently. According to experts at the Mayo Clinic, taking ulcer medication with alcohol leads to twice the wallop. Drink one beer, and you feel as though you’ve had two.
  • Diuretics, commonly known as water pills, increase urination, which increases your loss of the mineral potassium. To make up what you lose, experts suggest adding potassium-rich bananas, oranges, spinach, corn, and tomatoes to your diet.
  • Oral contraceptives reduce the body’s absorption of the B vitamin folate and possibly B12.
Battling Nutrients and Medications
You Absorb Less . . . When You Take . . .
Vitamin A Aluminum antacids Bisacodyl (laxative) Cholestyramine (lowers cholesterol) Fenfluramine (diet pill) Mineral oil (laxative) Neomycin (antibiotic)
Vitamin D Bisacodyl (laxative) Cholestyramine (lowers cholesterol) Mineral oil (laxative) Neomycin (antibiotic)
Vitamin K Bisacodyl (laxative) Cholestyramine (lowers cholesterol) Mineral oil (laxative) Neomycin (antibiotic)
Vitamin C Aspirin Barbiturates (sleeping pills) Cortisone and related steroid drugs
Thiamin Antacids (calcium) Aspirin Cortisone and related steroid drugs
Riboflavin Birth control pills
Folate Aspirin Cholestyramine (lowers cholesterol) Penicillin Phenobarbital, primidone, phenothiazines (antiseizure drugs) Sulfa drugs
Vitamin B12 Cholestyramine (lowers cholesterol) Neomycin (antibiotic)
Calcium Cortisone and related steroid drugs Diuretics (water pills) Magnesium antacids Neomycin (antibiotic) Phosphorus laxatives Tetracycline (antibiotic)
Phosphorus Aluminum antacids
Magnesium Amphotericin B (antibiotic) Diuretics (water pills) Tetracycline (antibiotic)
Iron Aspirin and other nonsteroidal anti-inflammatory drugs Calcium antacids Calcium supplements (with meals) Cholestyramine (lowers cholesterol) Neomycin (antibiotic) Penicillin (antibiotic) Tetracycline (antibiotic)
Zinc Diuretics (water pills)

Source: James J. Rybacki, The Essential Guide to Prescription Drugs 2002 (New York: Harper Collins, 2001); Brian L. G. Morgan, The Food and Drug Interaction Guide (New York: Simon and Schuster, 1986); Eleanor Noss Whitney, Corinne Balog Cataldo, and Sharon Rady Rolfes, Understanding Normal and Clinical Nutrition, 4th ed. (Minneapolis/St. Paul: West Publishing, 1994)