Foods to Avoid When Taking Your Bariatric Vitamins

Article By: Maria Tucker, MPH, RDN, LDN, CDCES

Maria Tucker is a Registered Dietitian and Certified Diabetes Educator with over 20 years of experience assisting patients with diabetes, obesity, and nutrition-related conditions.

As a specialist in bariatric surgery nutrition, I counsel patients on the appropriate dietary supplements to take, the recommended doses for these dietary supplements, and when to take them. It's easy to overlook the many medications that some patients may be prescribed and the interactions they may have with certain vitamins, minerals, and even food. In this article, we share a bariatric vitamin guide for patients following a bariatric diet.

Patients sometimes request a review of their medications to determine what medications, if any, they should avoid taking with their dietary supplements. Drug or food and vitamin/mineral interactions may have a negative effect on the efficacy of certain medications due to decreased or enhanced absorption of the drugs. Certain medications can cause nausea, unpleasant or metallic taste as well as dry mouth, which can decrease appetite or aversion to taking vitamin and mineral supplements, potentially leading to nutrient deficiencies.

Nutrients can affect drug absorption due to delay in digestion or (with certain minerals) by binding with the drug or promoting absorption of the drug. Certain nutrients may enhance or inhibit breakdown of some drugs, while other nutrients may alter reabsorption or excretion of the drug via the kidneys.

Certain drugs may cause an increase, decrease, or inhibit nutrient absorption in the gut. They may also speed up the nutrient breakdown leading to higher requirements for those nutrients, and drugs may also increase or decrease excretion of certain nutrients in urine.

To help you with determining the proper way to supplement post-bariatric surgery, here is a bariatric surgery nutrient supplementation guide, including medication-nutrient interactions, vitamin and mineral pairings to take or avoid taking together.

1) Examples of common medications & nutrient interactions.

Below are a few commonly prescribed medications that need careful consideration when taking vitamins and minerals, especially with the high doses of certain nutrients bariatric surgery patients take.

Medications Interactions
ACE Inhibitors – Lisinopril, Enalapril Do not take with calcium supplements as it may decrease absorption of the drug Avoid supplementation with potassium without supervision from your healthcare provider as it can lead to hyperkalemia (high blood potassium level)
Anticoagulants – Warfarin (Coumadin) Avoid vitamin K. Do not exceed upper limit for vitamins A and E
Antibacterials - penicillin, amoxicillin Caution when taking vitamin K
Antibiotics – tetracycline, ciproflaxin Do not take with iron or calcium carbonate as these may decrease absorption of the antibiotic
Beta Blockers – Metoprolol, Atenolol, Propanolol Do not take with calcium supplements as it may decrease absorption of the drug
Calcium channel blockers – amlodipine, nifedipine diltiazem, verapamil Do not take with magnesium to decrease risk of dizziness or low blood pressure
Histamine blockers – famotidine (Pepcid), ranitidine (Zantac) May decrease iron and vitamin B12 absorption
Loop Diuretics – furosemide, bumetanide, torsemide These drugs increase excretion of calcium; will need calcium supplementation
Non-Steroidal Anti-Inflammatory Drugs (NSAIDS), for example, ibuprofen May increase need for vitamin C, vitamin K and folate; high doses of vitamin C can increase the level of these drugs
Orlistat – Alli, Xenical May decrease absorption of vitamin D
Osteoporosis Drugs - alendronate Take magnesium at least 30 minutes after taking alendronate
Quinolones – ciproflaxin, levoflaxacin Do not take with calcium or magnesium as they may decrease efficacy of the drug. Take the drug 2 hours before or 6 hours after taking a supplement with magnesium
Retinoids – isotretinoin, acitretin Avoid taking with vitamin A due to risk of toxicity
Statins – atorvastatin, lovastatin, rosuvastatin Taking high doses of niacin with statins may increase risk of rhabdomyolysis (muscle breakdown)
Thyroid medications - levothyroxine Separate antacids or supplements containing iron or magnesium from thyroid medications by 4 hours as they may decrease efficacy of the drug

2) Examples of nutrients best taken together.

Certain vitamins and minerals are best taken together since they work together synergistically, meaning they increase the effect of the other. Here are some examples of nutrients best taken together.

Nutrient Pairings Effect of Pairing
Vitamin A, iron and copper Adequate vitamin A is necessary to move iron out of storage and incorporated into hemoglobin during production of red blood cells. Adequate copper is also important for this process. With decreased vitamin A, iron cannot mobilize out of storage, leading to fatigue.
Vitamin D, vitamin K and calcium Vitamin D helps absorb calcium from the gut while vitamin K, especially vitamin K2, helps distribute calcium into the bones.
Vitamin D and magnesium Taking magnesium with vitamin D may help ensure the body can properly use vitamin D
Vitamin D and omega-3 supplements Taking vitamin D with fish oil or omega 3 supplements can increase the bioavailability of both supplements.

3) Examples of nutrients best taken apart from each other.

On the other hand, certain vitamins and minerals should not be taken together. Below is a list of some nutrients best taken apart from each other. 

Nutrients to Avoid Taking Together
Calcium and Iron High doses of calcium, if taken together with iron, may compete for absorption in the gut
Magnesium and other minerals High doses of magnesium may compete for absorption of other minerals in the gut if taken together
Vitamin K and E Do not take vitamin K with high doses of vitamin E
Beta-carotene, lutein, lycopene, zeaxanthin Avoid taking with calcium or magnesium
Iron and caffeine Avoid taking iron with coffee or tea

4) A summary for bariatric patients.

Taking your bariatric surgery multivitamins with or without iron and other recommended supplements consistently is crucial to preventing vitamin and mineral deficiencies but following a healthy post-bariatric surgery diet is just as important to maintaining good health while losing weight post-surgery or keeping you at your goal weight long term. Whether you’re preparing for or have had bariatric surgery, a Registered Dietitian Nutritionist specializing in bariatric surgery can help you with your diet and nutrient supplementation needs. For questions about how to take your medications, consult your local pharmacist. Purchase your vitamin and mineral supplements from reputable companies to ensure the highest quality of the supplements you are taking.

BariMelts provides general recommendations, not to be construed as medical advice. Please consult your doctor.

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