| Therapeutic Class | Drug | Nutrient Interaction |
| Alcohols | Ethanol | Reduced absorption of fat, retinol, thiamin, cobalamin and folate; impaired utilization and storage of retinol; increased urinary excretion of zinc and magnesium. |
| Analgesics | Aspirin | Increased urinary excretion of ascorbic acid; may cause GI bleeding and subsequent iron deficiency; increased folate and vitamin D requirements. |
| Antacids | Al or Ca containing | Reduced iron, copper, phosphate and magnesium absorption. |
| Antibiotics | Penicillins Aminoglycosides Chloramphenicol |
Increased urinary excretion of amino acids; reduced intestinal vitamin K and cobalamin synthesis; possible malabsorption of fat, cobal- amin, calcium, magnesium and carotenoids. |
| Anticoagulants | Coumadin | Vitamin K decreases & tocopherol increases drug effect. |
| Anticonvulsants | Phenobarbital Phenytoin |
Folate antagonists; Increased vitamin D, vitamin K and pyridoxine requirements; Impaired vitamin D metabolism leading to hypomagnesemia, hypocalcemia and hypophosphatemia. |
| Antidepressants | Imipramine | May induce riboflavin deficiency; increased appetite. |
| Antihypertensives | Hydralazine | Pyridoxine antagonist; increased urinary excretion of manganese and pyridoxine. |
| Antimalarials | Pyrimethamine Sulfadoxine |
Folate antagonists. |
| Antineoplastics | Methotrexate | Folate antagonist; may impair fat, calcium, cobalamin, lactose, folate and carotene absorption. |
| Antitubercular | Isoniazid | Accelerated metabolism of pyridoxine - subsequent pyridoxine deficiency blocks conversion of tryptophan to niacin leading to niacin deficiency; reduced calcium absorption; reduced conversion of Vitamin D by the liver. |
| Antiulcer | Cimetidine | Impaired cobalamin absorption. |
| Cardiac Glycosides | Digoxin | Increased urinary excretion of calcium, magnesium and zinc. Anorexia. |
| Corticosteroids | Hydrocortisone Prednisone Dexamethasone |
Reduced calcium and phosphate absorption; increased urinary calcium, potassium, ascorbic acid, zinc and nitrogen excretion. Increased pyridoxine and vitamin D metabolic requirements. |
| Diuretics | Furosemide Thiazides Spironolactone |
Increased urinary potassium, sodium, chloride, magnesium, zinc and iodine excretion; reduced calcium excretion leading to hypercalcemia and hypophosphatemia with thiazides, increased calcium excretion with furosemide. Increased urinary sodium and chloride; reduced urinary potassium excretion. |
| Hypocholesterolemic Agents | Cholestyramine Colestipol |
Reduced absorption of fat, fat soluble vitamins, calcium, cobalamin, folate. |
| Laxatives | Bisacodyl Phenolthalein Mineral Oil |
Abuse leads to general malabsorption, steatorrhea and dehydration. Malabsorption of fat soluble vitamins, electrolytes,calcium. |
| Oral Contraceptives | Conjugated estrogens Ethinyl estradiol Mestranol |
Increased folic acid & possibly pyridoxine & ascorbic acid requirements; reduced calcium excretion, altered tryptophan metabolism. |
| Stimulants | Caffeine | Increased urinary calcium excretion. |