What does a Puppy and an Orange have to do with the Evolution of Man and Vitamin C?

With the stay at home and social distancing that has become our new-temporary-normal, in an attempt to keep my family healthy, I’ve also upped everyone's vitamin C intake. This ultimately means lots of oranges in the house. Our dog Levi, being an energetic nine-month-old silver Lab, wants to eat anything I have in my hands, so lately that means lots of oranges. I thought twice about giving him one because I had concerns about citrus and dogs, but then I thought if I gave him one slice, he probably wouldn’t eat it anyway. I wish I had videotaped the first time I shared an orange slice with him. It was funny, but ultimately he loves them. So I found myself researching, can citrus be harmful to dogs? If not, can dogs benefit from vitamin C as humans do? What I found was very interesting.

It seems that unlike humans, dogs can synthesize their own vitamin C. Which should mean that they don't need to take supplemental forms of vitamin C like humans do. Although more research shows that younger pups, older dogs, and any dog with a compromised immune system just might benefit from a supplement of vitamin C. In a situation where the dog is stressed, typically puppies going through vaccines, surgery, (dewclaws, ears, tails, neutering, or being spayed), and sometimes growth spurts can be a natural stressor. Older dogs become less proficient at making their own vitamin C and may benefit from getting doses through supplementation or diet. Veterinarians have used vitamin C to treat dogs with respiratory infections, abscesses, and other bacterial infections. Because vitamin C plays a significant role in the body's natural ability to synthesize collagen, some vets recommend supplementing vitamin C for degenerative joint disease, hip dysplasia, and spinal disorders. Vitamin C has also played a role in combating allergies in dogs. Ultimately even though dogs synthesize their own ascorbic acid many dogs benefit from vitamin C when added to their diet, or in a supplemental form.

My curious mind immediately went to the question of how come dogs can synthesize their own vitamin C and humans can't? I was hoping for an easy answer, but it seems that wasn't about to happen. It all starts with vitamin C biosynthetic pathways...yup, already difficult right? Somehow between catalysts and enzymes, encoded by a gene; glucose is turned into ascorbic acid. Humans lost the ability to synthesize vitamin C because of a gene mutation somewhere along the line in our vertebrae evolution, or simply put; we can't create our own vitamin C because of a broken gene. This article is fascinating if you’d like a peek at the long and slightly more complicated explanation by Alex Berezow, PhD.

Here is a list of fruits and veggies that are high in vitamin C. Supplementing simply means adding portions of these foods to your dog’s diet in small amounts. So while it's clear that most dogs benefit from vitamin C, always consult your veterinarian first, and knowing your dog's digestive issues is also key. Get the facts on size and dosing, go slow, and pulse back if Fido gets loose in the goose. For some dogs naturally enhancing through the diet may be just the boost they need, for other dogs a supplement may be required through further research and a veterinarians recommendation.

• Oranges

• Apples

• Sweet Potato

• Kiwi

• Broccoli

• Strawberries

• Brussels’ sprouts

• Cantaloupe

• Papaya

• Kale

• Peaches

• Parsley

• Thyme

So there you have it, dogs make their own vitamin C whereas humans lost the ability to synthesize their own somewhere in our evolutionary past. Giving Levi orange slices here and there isn't going to hurt him, the one thing we do hold in common with our four-legged friends is that too much vitamin C will just go right through us both...if you know what I mean. Actually giving Levi raw fruits and veggies with vitamin C could help his stress levels as he goes through growth spurts. If you have a puppy, an elderly dog, or a dog with a depressed immune system or bone and joint issues, supplementing his or her diet with raw sources of foods high in vitamin C, just might help.