Vitamins are essential to numerous biological processes. There are 13 in total. Let’s take a closer look at some of them.
There are two main types of vitamins, depending on whether they are fat-soluble (liposoluble) or water-soluble (hydrosoluble):
Fat-soluble vitamins are stored in fatty tissue and the liver. In excess, they pose a toxicity risk to the body.
Vitamin A – for vision and skin renewal
It is found in high concentrations in the liver and meat, but also in fish, eggs, and dairy products. It is also known as "retinol" because it notably enables adaptation to low-light vision. A vitamin A deficiency can lead to vision problems, skin disorders, reproductive issues, and increased susceptibility to infections, particularly respiratory ones. In excess, vitamin A may cause joint and reproductive disorders, among other issues.
Vitamin D – for calcium and phosphorus metabolism
Vitamin D3, the only form usable by dogs and cats, primarily comes from fish liver oils, fatty fish, egg yolks, or dairy products. It plays a key role in regulating calcium and phosphorus metabolism, which are essential for growth and bone mineralization. A deficiency in vitamin D, or calciferol, can lead to rickets and osteomalacia, but the opposite is more commonly observed—particularly in large-breed puppies. Excess vitamin D may cause ossification disorders (osteochondrosis).
Vitamin E – to combat cellular oxidation:
Oils, oilseeds, and cereal germs are the primary sources of this vitamin, which combats oxidative stress. It helps neutralize ROS—"reactive oxygen species" (link to e-mag on oxidative stress)—and thus protects against aging, cardiovascular diseases, cataracts, and neurodegenerative disorders. It also boosts immune defenses.
Vitamin K – For Blood Clotting:
Key sources include meat and vegetables. This vitamin, stored in the liver in dogs and cats, is absolutely essential for certain blood clotting factors. A deficiency can lead to digestive, nasal, skin, or even cerebral hemorrhages, ultimately resulting in anemia (a shortage of red blood cells, which transport oxygen).
Water-soluble vitamins can be excreted through urine, so the risk of overdose is lower.
Vitamin C – Fighting Oxidative Stress:
It is found in all plants, particularly citrus fruits and kiwi, but the livers of dogs and cats can also synthesize it. Ascorbic acid plays a key role as an antioxidant and is also involved in iron metabolism.
B-Group Vitamins – A Multitude of Benefits
There are many of them, and their functions can vary greatly. Vitamin B1 (or thiamine) is essential for the proper functioning of the nervous system; vitamin B2 (or riboflavin) contributes to healthy skin and coat; vitamin B12 (or cobalamin) is key in combating aging and anemia, as well as in protein synthesis; vitamin B9 (or folic acid) plays a role in the development of nervous system tissues and DNA synthesis… Their sources are also highly diverse: yeast and wheat germ for B1; yeast, liver, eggs, and dairy products for B2; exclusively animal-based products (liver, kidneys, fish, meat) for B12; and yeast, liver, and green vegetables for B9…
Sources:
Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs: Published annually by FEDIAF (The European Pet Food Industry Federation) and FACCO (the French Pet Food Manufacturers’ Federation), this guide outlines nutrient level recommendations for pet food.
All About the Nutrients That Nourish, Protect, and Heal Dogs and Cats: if you're passionate about pet nutrition, this book by Prof. Dominique Grandjean is a true goldmine of information!
