If you’re taking a prescription medication every day, it may be interfering with your nutrition—and your doctor may not know it. This problem is so common that I wrote the book Supplement Your Prescription: What Your Doctor Doesn’t Know About Nutrition.

Fortunately, you can protect yourself. When I treat patients who are taking prescription medications, I almost always prescribe specific nutritional supplements to head off deficiencies that the drugs can cause. Important: These are the minimum doses for my standard nutritional prescriptions. You may benefit from higher doses, which you should discuss with your health-care provider.

If you take metformin (Glucophage, Glumetza, Fortamet): This diabetes drug can deplete vitamin B-12. Metformin also may deplete the body of the antioxidant and cardiovascular protector coenzyme Q10 (CoQ10). A study published in Archives of Internal Medicine showed that people with diabetes taking metformin had B-12 levels that were, on average, less than half the levels of people not taking the medication. Metformin also depletes folate (vitamin B-9). You most often will see this vitamin supplied as folic acid, which is then metabolized in the body to folate. (It also can be supplied as methylfolate for poor metabolizers of folic acid.)

Daily supplements needed… 

• Vitamin B-12 (1,000 mcg)
• Folic acid or methylfolate (400 mcg)
• CoQ10 (100 mg)

If you take a corticosteroid such as prednisone, prednisolone, betamethasone, budesonide, triamcinolone, cortisone or methylprednisolone: While these anti-inflammatory drugs often are prescribed for short-term use to manage conditions such as allergic rashes, people with certain autoimmune conditions such as rheumatoid arthritis, Crohn’s disease, ulcerative colitis and lupus often take them indefinitely. The nutrients they can deplete include calcium, folate, magnesium, potassium, selenium, vitamin D and zinc.

Daily supplements needed…

• Calcium (600 mg). Note: Most of your calcium should come from food.
• Folate (400 mcg)
• Magnesium (400 mg)
• Potassium (99 mg)
• Selenium (100 mcg)
• Vitamin D (1,000 IU)
• Zinc (25 mg)

If you take an ACE inhibitor blood pressure drug such as benazepril ­(Lotensin), enalapril (Vasotec), lisinopril (Prinivil) or ramipril (Altace): These medications can deplete zinc.

Daily supplement needed: Zinc (25 mg).

If you take a calcium channel ­blocker for high blood pressure such as amlodipine (Norvasc), diltiazem ­(Cardizem), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nisoldipine (Sular) or verapamil (Calan, Covera-HS, Isoptin, Verelan): These medications deplete potassium.

Daily supplement needed: Potassium—the average daily requirement is 4.7 grams (4,700 mg), best obtained through eating potassium-rich foods ­including bananas, cooked spinach and many other fruits and vegetables. Supplements top out at 99 mg (found in your multi), while pharmaceutical supplements are higher but also contain a lot of unneeded chemicals. Have your potassium blood level checked, and go by your health practitioner’s recommendation.

If you take a beta-blocker for high blood pressure and/or heart disease: It can deplete CoQ10.

Daily supplement needed: CoQ10 (100 mg).

If you take a statin to reduce cholesterol: It can deplete the body of CoQ10, which is vital for heart health.

Daily supplement needed: CoQ10 (100 mg).

If you take an antibiotic even for a short time: It can deplete the nutrients biotin, inositol, vitamins B-1 (thiamine), B-2 (riboflavin), B-3 (niacin), B-5 (pantothenic acid), B-6 (pyridoxine), B-12 (cyanocobalamin) and vitamin K—and interfere with the beneficial bacteria in your gut. Also: Fluoroquinolones (any antibiotic that has a generic name that ends with the suffix “-floxacin,” including the well-known ciprofloxacin, aka Cipro), can deplete calcium and iron. Tetracyclines (ending with the suffix “-cycline”) can deplete calcium and magnesium. Trimethoprim-containing antibiotics (Trimpex, Proloprim, Primsol) can deplete folic acid. Penicillins (ending with the suffix “-cillin”) can deplete potassium.

Daily supplements needed… 

• You needn’t worry about how to find and take all those nutrients! The doses of magnesium, calcium and other nutrients contained in a good multivitamin/mineral supplement should cover your needs for these nutrients during a course of antibiotic therapy.

• Additionally, find a high-potency B-complex supplement that contains close to these ingredients and doses: B-1 (25 mg), B-2 (25 mg), B-3 (50 mg), B-6 (50 mg), folic acid (400 mcg to 800 mcg), B-12 (10 mcg), biotin (50 mg) and B-5 (50 mg). A “B-50” formula generally will provide these levels.

• B-12 (1,000 mcg), taken in sublingual tablets for better absorption.

• Vitamin K (30 mcg to 100 mcg)

• After a course of antibiotics, take a probiotic supplement to restore the beneficial bacteria in your gut. Choose one that contains at least one billion live organisms per daily dose and includes both Lactobacillus acidophilus (L. acidophilus) and Bifidobacterium bifidum (B. bifidum).