Medications That Deplete Your Dog’s Nutrients

Medications That Deplete Your Dog’s Nutrients

One of the most important tips I learned in my training with Dr. Richard Pitcairn was to write down a list of any drugs the patient is taking, then look up the effects of taking those meds in the VPB (Veterinary Pharmaceuticals and Biologicals). 

This information helped his students learn not just about drug side effects, but also about how medications can deplete nutrients. 

How Nutrients Interact In Metabolism

Our dogs’ metabolisms (like our own) are extremely complex. Every nutrient has an effect on other nutrients. Everything needs to work as it should to achieve good health (1). If one nutrient is out of place a significant number of other nutrients and functions are affected. For example. in the mammalian body (including dogs), zinc is involved in over 200 enzymatic reactions. Vitamin D is responsible for over 2,000 genes. Magnesium is one of the most important everyday nutrients and yet one of the most common deficiencies.

Pharmaceuticals Deplete Nutrients

All pharmaceuticals, vaccines, and nutraceuticals will deplete at least one critical nutrient in the body, usually by limiting nutrient absorption.

Micronutrient and macronutrient deficiencies can be caused by commonly used prescription medication. Critical nutrient deficiency is often the reason for adverse events that can follow many medications. This not only includes prescription medications but even over the counter (OTC) medications, which, if taken long enough, can lead to critical nutrient deficiencies.

The finding that up to 30 percent of drug side effects in humans are caused by drug-induced natural deficiencies was put forward by the late Frederic Vagnini MD and Barry Fox PhD in a March 2006 article, Preventing Pharmaceutical Induced Nutritional Deficiencies (2).

Dogs (and people) already eat foods grown in soils sprayed with pesticides and herbicides. The herbicide glyphosate, for example, is known to bind (chelate) critical minerals and trace nutrients and prevent plants from taking them up. Some irrigation water may include heavy metals that also chelate minerals necessary for healthy plants.

Added to this, pharmaceuticals (prescription and OTC), as well as synthesized or processed imitation nutritional supplements, are contributing to a potential epidemic of malnutrition. Malnutrition – specifically in the face of obesity and endocrine disease – is a problem for people as well as pets today. 

RELATED: Read about glyphosate, the harmful dog food ingredient hiding in your dog’s food … 

Do Veterinarians And Doctors Know Drugs Cause Deficiencies?

Usually, they don’t. This important information isn’t widely taught in medical or veterinary school. The nutritional deficiencies pharmaceuticals cause aren’t well-known in the medical or veterinary communities, despite books on the topic since at least the turn of the century – notably a handbook published in 2001 (Ross Pelton et al, Drug-Induced Nutrient Depletion Handbook 1999-2000; Lexi-Comp 2001). 

It would be a valuable service to tell patients what critical nutrients are affected by the drugs they’re prescribing … and to recommend remedial actions. Veterinarians should also be wary of recommending synthetic nutraceuticals or imitation nutrients. These can be as bad as or worse than pharmaceuticals. 

The patient should receive a whole food suggestion to replenish critical nutrients. Whole foods have bioavailable forms of the nutrient that the body recognizes and can use as nature intended.

Nutrition Depletion Effects Of Common Drugs

Original research uses mammalian animals. Rodent studies cost much less than canine studies, which in turn cost much less than primate studies. Most of the research done is on mammals and the results apply to all mammals, including humans. So when we’re talking about the immune system being essentially the same in dogs and humans, we’re referencing research that’s verified this link. Since many of the drugs used for humans are the very same used for dogs (sometimes with a different name), the depletion of nutrients and health impact on your dog is the same as it is for other mammals.

The drugs below are all drugs frequently prescribed to dogs.


Antibiotics in general destroy the “good” bacteria (probiotics) in the gastrointestinal tract, causing deficiencies in these nutrients: B vitamins; B1, B2, B3, B5, B6, B12, biotin, inositol, folate, and vitamin K.

Penicillin depletes potassium, all of the B vitamins, vitamin K, vitamin C, and the probiotics necessary for gastrointestinal and overall health. A broad-spectrum antibiotic like Clavamox causes common complaints of cramping and nausea because it disrupts important microflora in the entire body.

Tetracyclines like doxycycline deplete calcium, magnesium, iron, zinc, vitamins B6 and B12, vitamin K, vitamin C, and again the important probiotics.

Trimethoprim Sulfa (Ditrim) not only causes dry eye but also depletes folic acid. Sulfa drugs and trimethoprim deplete biotin, folic acid, inositol, B vitamins, vitamin K and of course the friendly bacteria needed for health.

Macrolides (some canine heartworm medications are in this class) deplete vitamins B1, B2, B3, B6, and B12, folic acid, vitamin K, biotin, inositol, and again the friendly bacteria.

Fluroquinolones like Baytril and Cipro deplete vitamins B1, B2, B3, B6, and B12, folic acid, vitamin K, biotin, inositol, calcium, magnesium, iron, potassium, and the probiotics.

Cephalosporins deplete vitamins B1, B2, B3, B6, and B-12, folic acid, vitamin K, biotin, Inositol, and once again the important friendly bacteria.

Neomycin depletes beta carotene, calcium, magnesium, iron, potassium, and vitamin B12.

Caution: Mineral supplements (magnesium, calcium, zinc, iron, selenium, iodine) should be taken at least two hours before or after antibiotics because they can bind to the drug and reduce drug absorption.

Remember, the probiotic-friendly bacteria that are harmed by taking antibiotics are crucial to your dog’s healthy digestion, assimilation of nutrients, immune system, plus his mental health and behavior.

RELATED: Vitamin B12 deficiency in dogs …


Anticonvulsants are anti-seizing medications that are often prescribed long term after vaccine-induced seizures. 

Barbiturates deplete calcium, folic acid, vitamin D, vitamin K, and biotin.

Phenytoin depletes biotin, calcium, folic acid, phosphorus, carnitine, and vitamins B1, B12, D, E K. 

Carbamazepine depletes biotin, folic acid, and vitamins D and E. 

Primidone depletes biotin, calcium, folic acid, and vitamins D and K. 

Valproic acid depletes folic acid, carnitine, copper, selenium, zinc, and vitamins B6, E. 

Neurontin (gabapentin) depletes vitamins B6, B12, A, D, and K, folic acid, biotin, carnitine, calcium, and magnesium. Fatigue will occur unless the carnitine is replenished. Gabapentin is also used for pain management in dogs. 

RELATED: Learn why one vet won’t ever prescribe Gabapentin for dogs … 

Anti-Inflammatory Drugs

This is a big drug category that’s popular in treating what I see mostly as a vaccine-induced disease. In this category first up are …

Corticosteroids. Taking this medication may deplete, increase the need for, or interfere with the activity of the following nutrients: vitamins A, B6 and B12, C, D, and K as well as folic acid, calcium, magnesium potassium, selenium, zinc, and chromium.

Non-steroidal anti-inflammatory drugs (NSAIDS)  deplete folic acid and melatonin. it is no wonder that sleeping disorders can develop in patients taking these kinds of drugs. Melatonin is also a very important anti-cancer hormone and antioxidant. Circadian rhythms can also be adversely affected if the melatonin is depleted.

RELATED: Melatonin for dogs: not just for sleep … 

Heart Medications

Heart medications in general present a real risk. Some frequently prescribed categories are listed below. The very reason so many heart patients present in an emergency state with cardiac arrhythmias that require lifesaving injections is because of electrolyte imbalances created by the heart medications prescribed in the first place! The medications themselves cause potassium that is too high or too low and magnesium that’s usually too low. The EKG or electrocardiogram shows the effects of nutrient depletion or imbalances generated by the prescription medications. Low potassium or low magnesium can lead to Torsade de Pointes (ventricular tachycardia).  High potassium can cause idioventricular rhythms or accelerated idioventricular rhythms; low potassium and electrolyte imbalances can trigger SVT (supraventricular tachycardia), preventricular contractions, or ventricular tachycardia. Often the effects are lethal for patients.

Diuretics (like loop diuretics) deplete potassium, magnesium, calcium, vitamins B1, B6, C, sodium and zinc. Potassium-sparing diuretics deplete calcium, folic acid, magnesium, phosphorus, zinc. The thiazide diuretics deplete magnesium, potassium, sodium, zinc and CoQ10.

Beta Blockers can reduce CoQ10 and melatonin.

Ace inhibitors deplete zinc and potentially sodium, vitamin B6, magnesium, phosphorus, potassium, and CoQ10

Angiotensin II Receptor Blockers deplete zinc, calcium, magnesium, phosphorus, and CoQ10.

Any drug that depletes CoQ10 can affect brain, muscle, and heart function and energy levels, for which CoQ10 is a critical nutrient.

Calcium Channel Blockers deplete vitamin D, magnesium, potassium.

RELATED: A holistic approach to congestive heart failure in dogs … 


Vaccinations can lead to vitamin C deficiencies. This is especially so when vaccines are given to individuals who might have vitamin-deficient diets in the first place. This depletion was discovered in Aboriginal Australian children who were vaccinated while their diets were low in vitamin C. Nearly half died shortly after vaccination, but when they received vitamin C prior to vaccination, none died. 

Vaccines should never be given in the face of deficiencies of vitamins C, D, or A, or deficiencies of zinc, magnesium, or selenium. (Actually, vaccines should never be given to any being who isn’t perfectly healthy.)

Other Medications

Antifungal medications like Amphotericin deplete calcium, magnesium, potassium and sodium.

Antihistamines (such as the greatly over-prescribed Benadryl), which some dogs are given long-term to combat allergies, will deplete omega-3 fatty acids in the body. Omega-3s are critical nutrients for brain, heart, skin, immune system, and joint health – and ironically they can also help manage allergies, the very complaint most antihistamines are used for!.

RELATED: Read why Benadryl isn’t safe for your dog … 

Some veterinarians prescribe tricyclic antidepressants to dogs. These deplete vitamin B2 and coenzyme Q10 (CoQ10)

SSRIs (selective serotonin reuptake inhibitors), another type of antidepressant used to treat dogs, deplete melatonin and iodine. 

Serotonin antagonist and reuptake inhibitors (SARI) deplete CoQ10 and vitamin B12.

Thyroid medications can deplete the amount of iron in the body.

Medications for protozoa like giardia deplete magnesium.

Mammalian bodies are amazing and complex but can’t remain healthy if not fed properly … or if they’re medicated, improperly supplemented, or vaccinated into further critical nutrient depletion.

To learn about natural alternatives to replace drugs, nutraceuticals, or vaccines that affect nutrients, I recommend contacting a properly trained holistic or naturopathic veterinarian

  1. Chen Y, Michalak M, Agellon LB. Importance of Nutrients and Nutrient Metabolism on Human HealthYale J Biol Med. 2018;91(2):95-103. Published 2018 Jun 28.
  2. F Vagnini, B Fox. Preventing pharmaceutical-induced deficiencies. Life Extension 2006. 
  3. Meletis, CD, Zabriskie, N. Common Nutrient Depletions Caused by Pharmaceuticals. Alt and Comp Ther 2007 131, 10-17.

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