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The Dangers of Synthetic VS Whole Food Supplements for Pets

When you first become invested in your dog or cat’s health, an ideal all-in-one, complete and balanced food for them is a compelling concept. But there are downsides and dangers to focusing solely on getting every single nutrient into every single meal without taking a closer look at what exactly is going into those meals to make them complete and balanced. In the end, not all nutrients are created equally—they either come naturally from whole foods or are synthetically derived, and the difference is important!

jack russel terrier dog hand giving synthetic medicine pill

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How Vitamins are Stored in the Body

In simple terms, there are two types of vitamins: water-soluble and fat-soluble. Water-soluble vitamins include B-complex and C vitamins. Water-soluble vitamins are hard to overdose on—your pet’s body absorbs what it needs and discards the rest during their next visit to the bathroom.

Fat-soluble vitamins are more complicated. These include vitamins A, D, E, and K. These vitamins don’t get excreted regularly; they get stored in the fatty tissue of the body and liver, so taking too much of these minerals can lead your pet down the road to vitamin toxicity. When we think about which fat-soluble vitamins we should be concerned about, we’re primarily looking at A and D, as you’d have to feed your pet an unusually high amount of vitamins E and K to reach levels where toxicity becomes a risk.

How Vitamins Can Reach Toxic Levels in Pet Food

You might think that companies who tout all-in-one meals with adequate vitamins would be cautious about including toxic loads of vitamins in their meals, and normally you’d be right.

However, mistakes can happen, and when it comes to synthetic vitamins, even a little mistake can have huge consequences. Synthetic vitamins are cheaper to produce than those from whole food items, so it makes sense that companies who are interested in cutting costs might reach for these first. With that said, they’re also much more concentrated than vitamins from whole foods, so tipping over from “just enough” to “way, way too much” can happen quickly.

Companies that use synthetic vitamins will often get them in a vitamin/mineral premix from a third-party manufacturer. The pet food company may test these mixes religiously, once, occasionally, or just rely on the manufacturer’s analysis and not do any testing of their own.

Additionally, these manufacturers can sell their vitamin/mineral premixes to multiple pet food companies, so if there is a miscalculation in their premixes that doesn’t get caught, it can affect multiple pet food varieties and brands.

However, we’ll never be one to deny that there is a risk of vitamin toxicity from some whole food sources. Cod liver oil, for example, is high in vitamin D and sometimes has vitamin A added to it. With that said, your pet would have to ingest quite a bit of cod liver oil, to the point where the formula would be a noticeably different texture. Alternatively, they might consume it with another food source that was very high in vitamin A, like liver, so that the contents are cumulative. This is another reason you need to understand your pet’s food nutrients clearly and supplement according to their food and weight.

female vet doctor holding fresh foods and synthetic supplements

Why Avoiding Synthetic Supplements Is in Your Pet’s Best Interest

Fine, you might say, but the brand I feed my pets always has accurate synthetic vitamins in it—which, we might add, is a bold claim, but fair enough, let’s say this company with precise and consistent synthetic vitamin supplements exists. It’s still not the best option for your pet!

When you use whole food ingredients, you have millennia of evolution helping your pet absorb and digest those ingredients. Their body knows exactly what it needs and can readily extract those nutrients and efficiently discard the rest as waste. Whole foods also have the added benefit of other trace minerals and vitamins to help round out your pet’s nutritional needs, rather than a strict regimen of select synthetic supplements.

There are also complex interactions between all of the nutrients contained in whole foods and how the body will process them. For example, some whole foods may have substances that enhance the absorption of certain nutrients while blocking or limiting the absorption of others. While these concepts are not well understood or studied extensively in every food, any progress we’ve made so far is thrown out the window when you go about isolating a particular nutrient in a synthetic supplement.

On the other hand, synthetic supplements, in the same vein as processed foods, require your pet’s body to work harder to recognize the substance as a nutrient and then absorb it without the additional trace nutrients whole foods can provide. The harder their body works just to meet their basic needs means an increased risk of inflammation, which can lead to a whole host of other problems down the road.

Signs of Vitamin Toxicity

Vitamin toxicity can begin by just looking like your pet is under the weather. However, without identifying and correcting the issue promptly, they can easily lead to further complications and potential death. So while this list is by no means exhaustive, these are some signs to keep an eye out for in regard to vitamin toxicity. Keep in mind that these symptoms could be caused by any number of other issues; however, no matter what you think the precipitating cause is, they all deserve prompt veterinary attention.

Signs of Vitamin A Toxicity:

  • Rough, dry, or otherwise unhealthy skin and coat

  • Weakness

  • Weight loss

  • Pained or limited movement (limping or stiffness, etc.)

  • Constipation

  • Unusual or excessive bone growth (i.e. bone spurs)

  • Vomiting (in severe cases)

Signs of over-supplementing vitamin A can sometimes take weeks or months to show up; in instances in which your pet ingests a large dose of vitamin A, symptoms may occur within hours.

Signs of Vitamin D Toxicity

  • Vomiting

  • Diarrhea

  • Frequent urination

  • Weight loss

  • Lack of appetite

  • Excessive thirst

  • Excessive drooling

Signs of vitamin D toxicity generally show up quickly, within hours or days.

Pet food bowl with a variety of fresh vegetables, raw meat, and yogurt

The RDBK Promise

Here at RDBK, we’ve thought a lot about whole foods versus synthetic vitamins. As we mentioned before, synthetics are cheaper and easier to add to pet food than whole foods, and they allow for precise nutrient dosing (as long as it’s done correctly every single time, which isn’t guaranteed to happen!) But as with all things, we have to ask ourselves: is it too good to be true?

And that’s the conclusion we came to. We decided we would rather create meals with whole foods that offer the vitamins and minerals your pet needs without the risk of overdosing if a single iota too much of any ingredient gets mixed into their meals. This means our meals aren’t perfectly consistent—one carrot may have a tiny bit more vitamin A than another, but that’s how whole foods work, and it’s how we feed ourselves. With a bit of rotation and variety, everything balances out in the end.

Here are some examples of whole foods we use and the vitamins they contain:

  • Liver: Rich in vitamin A, vitamin B12, riboflavin (vitamin B2), niacin (vitamin B3), and vitamin B6.

  • Kidney: Vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6, vitamin B12, and vitamin D.

  • Celery: Contains vitamins A, C, and K, as well as folate and potassium.

  • Blueberries: Rich in vitamin C, vitamin K, and manganese, and also contain smaller amounts of vitamins B6 and E.

  • Bok choy: A good source of vitamin A, vitamin C, and vitamin K, as well as folate and calcium.

  • Butternut squash: Contains high amounts of vitamin A and vitamin C, as well as smaller amounts of vitamins B1, B3, B5, B6, and E.

  • Sunflower seeds: Contain vitamin E, thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), and vitamin B6.

  • Black soldier fly larvae powder: Contains high amounts of protein, calcium, and iron, as well as smaller amounts of B vitamins, such as thiamine (vitamin B1), riboflavin (vitamin B2), and vitamin B12.

  • Kelp powder: Rich in iodine, which is important for thyroid function, as well as small amounts of vitamins A, C, E, and K, and B vitamins such as thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), and folate.

…and that’s just to name a few!

One Last Dose

While the idea of an all-in-one, complete and balanced food for your pet may seem ideal, it's important to take a closer look at where the nutrients in their meals are coming from. Not all nutrients are created equally, and there are downsides and dangers to focusing solely on getting every single nutrient into every single meal. Without careful monitoring and control measures, synthetic vitamins can be a much greater risk to your pet's health than any naturally occurring vitamin contained in any healthy whole food fed in normal amounts could possibly be. By understanding the different types of vitamins, how they are stored in the body, and the possible signs of vitamin toxicity, you can begin to make healthier—and safer—choices for your pet. Whole foods, by contrast, offer all the same benefits—and more!—in terms of nutritional bioavailability, phytonutrients, antioxidants, fibre, and moisture content, and are significantly less likely to cause vitamin toxicity, even when they’re not “perfectly” balanced.

We bet they’ll taste better, too!


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