Vitamin K

Q: I have heard that vitamin K3 is toxic in pets. Is that what the menadione is in your foods?

A: Yes, there is a minute amount of K3 in the Wysong dry cat and dog diets (only), as well as some K1 from the natural ingredients themselves.

As for the current rumor that K3 is toxic in pets, consider the following.

The National Research Council Committee on Dog and Cat Nutrition, which is composed of 10 experts in the field of dog and cat nutrition, has just recently (2006) released the new N.R.C. publication, "Nutrient Requirements of Dogs and Cats."  The requirements and recommendations they give are in terms of menadione without any qualification as to source.  If menadione (K3) was toxic to dogs or cats at the levels commonly used, these folks would most assuredly have addressed the situation in this publication and their requirements/recommendations would be specifically stated in terms of K1. Since they do not make any attempt at distinction, it must be concluded that the members of this committee accept K3 as being safe for use in cat/dog foods.

Admittedly, the experts can be wrong. But in this case, with over a half century of use, and millions of animals fed K3 through generations with no reported toxicity at recommended inclusion rates, it is likely that they are not.

Additionally, common sense would indicate that, if the common vitamin K sources used in feeds for all kinds of animals, including birds, mammals and fish, were at all toxic, in any species, at the levels commonly used, the use of these vitamin K sources would have ceased very shortly after their introduction more than 50 years ago.

In the 1985 NRC "Nutrient Requirements of Dogs," the 6-member panel of experts on dog nutrition makes the following statement (page 27): "Although it is doubtful that supplemental vitamin K is necessary for the normal dog, it may be prudent to provide 22 micrograms of menadione (or vitamin K equivalent) per kilogram of body weight daily for adult maintenance and 44 micrograms per kilogram of body weight during growth. This would be more than supplied by a dry diet concentration of 1.0 mg of menadione per kilograms."  This quote is also cited in the 2006 publication.

The toxicity reported is manifest as the formation of Heinz bodies in red blood cells and a dose of 2.5mg per pound of body weight per day was required in the diet to produce that effect. The amount used in Wysong foods is approximately 7,000 times less than that!

This consideration plus the fact that Wysong cat foods and dog foods have been fed to tens of thousands of pets through several generations over a period of 30 years with no toxic effects - only benefit - is reason for every confidence.

Please keep in mind that every ingredient in any pet or human food is potentially toxic at high enough levels. The dose makes the poison. Oxygen and water are essential to life but toxic at high enough dose.

Pet owners are wise to see the constant alarms about this or that ingredient in pet foods for what they are, marketing attempts (not well reasoned science or evidence) by companies trying to make demons out of competition.

Because heat extrusion can diminish the levels of many important nutrients in pet foods, we feel the benefits of small insurance amounts of vitamin K in addition to the natural K present in our foods is prudent and can only bring benefit.

Vitamin K functions include:

• Needed for blood clotting

• Protects against osteoporosis

• Prevents oxidative cell damage