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Synthetic Vitamins/Minerals in Dog Foods

For 25 points, the answer is menadione bisulfite, which may cause anemia.

The question is, what’s Vitamin K in “natural” pet food?

For 50 points, the answer is retinyl palmitate, which may cause loss of appetite, irritability or bone changes.

The question is, what’s Vitamin A?

For 100 points, the answer is ascorbic acid, which may cause diarrhea, dry nose or nose bleeds.

The question is, what’s Vitamin C?

Pet owners have long ago learned to inspect pet food labels for meat terminology, order of protein and grain sources and presence of artificial preservatives. But how many discerning pet parents know how to review the long list of vitamins and minerals on the package?

Who would think that these could be the most detrimental of all the ingredients?

Why are vitamins and minerals added to dog foods?

Don’t vitamins and minerals occur naturally in the foods we eat?

To put it simply, there are not enough in processed foods to prevent disease. When a meat, grain, vegetable or fruit is cooked or heat processed in any manner, nutrients are lost to varying degrees. This is an accepted fact in the pet food industry. The industry is aware that certain minimum levels of vitamins and minerals are necessary to avoid devastating disease. The same industry is aware that excesses of synthetic vitamins and minerals can also cause devastating disease. Consumers have been trained to believe that foods that are approved by the pet food industry watch dog, the American Association of Feed Control Operators (AAFCO) are safe and balanced.

But, are they?

Why we need synthetic ingredients

In order to gain AAFCO approval, a pet food must meet a feeding trial requirement or a standard vitamin and mineral requirement. The least expensive way to meet this requirement is to add an accepted blend of premeasured synthetic vitamins and minerals to a processed diet.

Another way would be to add large amounts of healthful foods, which would provide enough nutrition despite the processing, but expensive testing or feeding trials would be necessary to prove the foods are adequate. For this reason, most manufacturers add the standard vitamin-mineral mix. This mix may be added to canned, kibble, freeze dried, or even commercial frozen raw diets.

How can you recognize the vitamins and minerals on the ingredient label?

Grab a bag of kibble. If it calls itself “natural,” it quite likely also states “with added vitamins and minerals.” AAFCO requires this statement because the vitamins and minerals are synthetic, not natural. The group is usually listed in the middle to bottom of the ingredient label, as all ingredients are listed in order of weight. Most of the names will sound like chemicals.

Here is a typical sample “natural” brand with added vitamins and minerals:

Chicken, Chicken Meal, Brown Rice, Oats, Barley, Rice, Menhaden Fish Meal, Chicken Fat (preserved with mixed tocopherols) Natural Chicken Flavors, Flaxseed, Dried Egg Product, Potatoes, Carrots, Herring, Natural Flavors, Whole Eggs, Apples, Carrots, Sweet Potatoes, Herring Oil, Dried Kelp, Potassium Chloride, Dicalcium Phosphate, Salt, Garlic, Vitamin E Supplement, (various fermentation products), Calcium Carbonate, Choline Chloride, Zinc Sulfate, Vitamin A Supplement, Vitamin D3 Supplement, Ferrous Sulfate, Copper Sulfate, Manganese Sulfate, Niacin, Calcium Pantothenate, Vitamin B12 Supplement, Folic Acid, Riboflavin, Sodium Selenite, Pyridoxine Hydrochloride, Calcium Iodate, Thiamine Mononitrate, Biotin, Cobalt Sulfate, Rosemary Extract.

Unnatural vs natural, does it matter?

Let’s analyze just one mineral out of the above list of synthetic additives: sodium selenite.

Sodium selenite contains selenium. When we eat natural, unprocessed, whole foods such as nuts, meat, mushrooms, fish or eggs, we eat selenium that is complexed and consumed along with other nutrients which help the selenium function properly in the body. “Humans and animals derive selenium primarily from foods. In plants and animals, selenium is primarily localized in the protein fraction” (Ferretti and Levandar, 1976). Brazil nuts are the richest dietary source of selenium. High levels of selenium are also found in kidney, tuna, crab, and lobster. But, these foods contain selenium, not sodium selenite.

“Both mutagenic activity (cancer causing) and antimutagenic (cancer preventing) activity have been attributed to selenium; the concentration and the chemical form in which selenium is administered appear to be critical in determining its effects. At the trace levels normally found in biological systems (plants and animals), selenium apparently acts as an antimutagenic, oxygen-radical scavenger, but at higher concentrations selenium is capable of inducing mutations (cancer). Arciszewskaet al, 1982; Shamberger, 1985; Kramer and Ames, 1988

Where does sodium selenite come from anyway? Sodium selenite is prepared by evaporating an aqueous solution of sodium hydroxide (lye or drain cleaner) and selenous acid (Merck Index 1983). Selenous acid is produced by combining water and selenium dioxide which is produced during the industrial purification of copper.

Does this sound like something we should eat?

According to the National Institute for Occupational Safety and Health (NIOSH), “prolonged exposure to sodium selenite may cause paleness, coated tongue, stomach disorders, nervousness, metallic taste and a garlic odor of the breath. Fluid in the abdominal cavity, damage to the liver and spleen and anemia have been reported in animals.”

Do you know any pets with these disorders?

How many times have you heard a pet parent comment that a change from kibble to fresh raw food improved the pet’s breath? Interesting!

The selenium we want to eat is a trace element, which is a cofactor for reducing antioxidant enzymes, found in animals and most plants. This biologic source of selenium is crucial to the proper functioning of every cell in the body, especially the thyroid gland. Selenium may inhibit Hashimoto’s disease, the human version of autoimmune thyroiditis, which has reached epidemic levels in our dogs. Selenium can even reduce the effects of mercury toxicity.

Can cells recognize unnatural vitamin and mineral sources?

In addition to the realization that unnatural sources of selenium can be toxic, their presence can inhibit the ability of

natural sources to function properly in the body. Cells have receptor sites for the attachment of biologic factors which turn on and off cellular functions. These receptors can become “clogged” with lookalike vitamins or minerals.

This phenomenon can explain why the initial consumption of a synthetic vitamin or mineral or even hormone replacement therapy works initially, when the receptor sites are empty and desperate for the nutrient. But, when the receptors become clogged with the inadequately functioning faux nutrients, the cell receptors cannot function properly. You or your pet may feel great after beginning a new synthetic supplement, or even a new type of diet, only for the original symptoms to recur after some time passes.

It’s important to remember that the problem doesn’t start and end with selenium. Every synthetic vitamin and mineral carries similar risks and shortcomings.

Solutions for the synthetic nutrient dilemma:

Consumer Demand

When most pet foods contained artificial preservatives (BHA, BHT, ethoxyquin), it was consumer pressure that drove the industry to manufacture their pet diets without them. It will likely be pet owner education and consumer demand that will again cause the industry to produce pet diets without these toxic vitamin and mineral additions. Many brands of raw food and at least one brand of kibble and canned already exist to fulfill this need.

One of the most devastating recalls in recent pet food history occurred when a reputable manufacturer accidentally dropped too much of a synthetic vitamin into the recipe. Dogs died. Generally, too much of a whole food source, like oranges or Brussels sprouts, will at worst cause some raging diarrhea but the body can recognize and purge the excess appropriately! This can’t happen with their synthetic counterparts.

Pet food costs are rising but loving pet parents have realized that healthy foods cost more and they are willing to pay for safe and effective supplements and food. As manufacturers realize there is a consumer need and willingness to purchase, they’ll respond by producing better and better pet diets.


Pet owners must continue to seek out nutritional education and not be swayed to purchase foods based just on high cost or influential marketing. Dog and cat lovers need to become aware of and support companies who produce ethically.

Purchase species appropriate, fresh foods and treats. Learn to read ingredient labels. Share this information with family, friends and fellow pet enthusiasts. Encourage veterinarians and other pet providers to be open minded. Don’t just accept the status quo. Disseminate information and ask good questions!

Whole Food Supplements

In our decaying world where soils devoid of nutrients are producing plants and animals with vitamin and mineral deficiencies, we must realize the solution is NOT to fill the gap with synthetics, but rather seek out whole food sources.

Fresh diets can be analyzed to ascertain the adequacy of nutrients. A body can thrive on smaller amounts of whole food source vitamins than it can on their synthetic counterparts. If the addition of a vitamin or mineral nutrient is necessary, it should ideally be added from a whole food source. Manufacturing processes exist which can concentrate the whole food vitamins available from cruciferous vegetables, berries and herbs and other plants. Organ concentrates can also be used as nutrient resources to prevent and repair a myriad of disorders.

The solution to pet food safety and nutrition is not in the laboratory. It lies in the unlocking and conscientious use of the abundant treasures from Mother Nature.

Jodie Gruenstern DVM CVA has been practicing veterinary medicine in Muskego, Wisconsin since 1987. She is a certified veterinary acupuncturist and food therapist by the Chi Institute. Dr. Jodie is the owner of the Animal Doctor Holistic Veterinary Complex, an integrated, full-service small animal practice. For more info and healthy products visit or

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