menadione

You can read the entire menadione article [linkhttp://www.dogfoodproject.com/index.php?page=menadione]here[/link]. The trouble is that the research was done overseas and it hasn't been studied here, so most people tend to dismiss it. However, the conclusions they came to in their research lead to it being banned in some countries. It is nasty stuff, but it's nothing to really freak over. I don't think that short-term (up to several months) feeding is going to be a problem. It's when it builds up in cells long-term that it becomes a serious problem. That said, I don't think it has ever been studied in dogs - but I wouldn't give my dog a synthetic substance that has been banned for human use [sm=2cents.gif] (Oh, and a lot of the Purina foods do have menadione)

it also seems odd to me that the cheaper brands like Purina don't have menadione in them whereas the super premium brands do.

 
Which super premium brands do have it?

Without looking I don't remember the whos exactly, but I know that Blue Buffalo and Newmans Own have menadione. I also know that Wellness didn't used to..then when they came out with the "new improved formulas", they did. Now the rep tells me that they have taken it out and that soon the bags will reflect that change. Not too long ago Natures Variety had it in their formulas..but looking at their web site I am not seeing it..so perhaps they have taken it out as well.

Mordanna posts updates about the removal of menadione on the home page of www.dogfoodproject.com

Blue, Newman's, Wellness, and Nature's Variety have all removed menadione or have plans to remove it.

     I'm not completely convinced menadione is necessarily a bad ingredient. IMHO, you may be missing out on some great foods due to a vitamin that is listed last or next to last on the list, meaning its not in the food in any great quantity.
     Personally, I'm more concerned with the quality control bioavailability of the food. Most synthetic vitamins will cause problems if taken in copious amounts, but my opinion is the Vit K thing has been blown way out of proportion! In fact, I've noticed that 3/4 of the foods I regularly use and get the best results out of happen to contain menadione [sm=2cents.gif]

Personally, I'm more concerned with the quality control bioavailability of the food. Most synthetic vitamins will cause problems if taken in copious amounts, but my opinion is the Vit K thing has been blown way out of proportion! In fact, I've noticed that 3/4 of the foods I regularly use and get the best results out of happen to contain menadione

 
Amen, I get tired of the crying wolf all of the time, some obscure study is cited where the duration of the tests and the dosages consumed are very vague or not cited at all.  In large doses and over an extended eriod of time almost anything can be harmful, even water.

The study isn't obscure, it's just German. And that study resulted in the substance being banned in many European countries where they had previously documented human damage and death. Even in the US, although they have never studied it, the FDA has banned it from supplements because of its toxicity. It has never been researched for long term use. All very good reasons for me not to take the chance with it.
 
Besides, if there's nothing wrong with it, why are so many companies removing it?

Besides, if there's nothing wrong with it, why are so many companies removing it?

 
Because the customers are asking for it to be removed, if it is dangerous, why is it allowed to be in pet food, when the FDA requires anything in pet food to be safe, and they have studies showing it is safe, why isn't a certain site objective and show studies on both sides instead of just showing studies which support her position.
 
Here is what the studies supported by the NRC say about it.
 
Even very large amounts of menadione compounds are tolerated well by animals. Seerley et al. (1976) fed 110 mg/kg of MPB to pigs, and Oduho et al. (1993) fed 300 mg/kg of MPB to chicks; neither observed signs of toxicity. A dietary level of 3,000 mg/kg of MPB did not depress weight gain or blood hemoglobin when fed over a 14-day period to chicks. It appears that menadione levels of 1,000 times an animal's requirement are well tolerated (National Research Council, 1987; Oduho et al., 1993).
 
 
There is also a lot of anecdotal evidence that it is an anti-carcinagen.
 
Menadione (150-200 mg/day IV), as a radiosensitizing agent, was discovered to increase survival time (5.42 months with menadione and radiation versus 3.77 months with radiation alone) in inoperable bronchial carcinoma patients. (36) Pretreatment of mice with transplanted mouse liver tumors by oral or intraperitoneal injection of vitamins K3 and C greatly potentiated the action of radiation (20-40 Gy dosages) compared to controls. (37) In rats, menadione was active against adriamycin-resistant leukemia cells. (3 Hepatoma-bearing rats receiving intraperitoneal injections of menadione (10 mg/2mL weekly for four weeks) demonstrated an increased survival rate of 60 days compared to 17 days for controls (five of 16 lived longer than controls). (15) The anticancer activity of menadione has also been demonstrated in a number of in vitro studies using both rodent (10,39-42) and human cancer cell lines. (11,12,43-45) Menadione was effective against multidrug-resistant leukemia cell lines and parental leukemia cell lines. (43)
 
Why doesn't a supposed unbiased dog food site show both sides of the story?

Natures Balance doesn't use it.....

Some Manufacturers have also started to address this issue on there websites.
 





Q: I have heard that vitamin K3 is toxic in pets. Is that what the menadione is in your foods?
 
W: Yes, there is a minute amount of K3 in the Wysong dry extruded 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 now (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 Diets have been fed to tens of thousands of pets through several generations over a period of 25 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

Natural sources include: Spinach, Brussels sprouts, Swiss chard, carrots, green string beans, asparagus, red bell peppers, strawberries and eggs, tomatoes, and green peas.

 
 

It still hasn't been studied for long-term use in dog food at any level. Sorry, but if there is information showing it causes damage and death to humans, and it's banned in some countries and for some uses here, it isn't something *I* want to feed my dog. There are too many great products that don't have it, and more are removing it all the time.

I, personally, wouldn't feed my dogs a food which contained menadione.  There are so many great foods out there that do not use it as an ingredient, and many foods are already removing it from their products. 

People need to feel comfortable feeding whatever they want, my personal opinion is that it is much to do about nothing.  Keep in mind that zinc, copper, manganese vitamin A, vitamin D and several other minerals and vitamins, are all toxic to dogs, so I don't think it is a huge surprise that vitamin K3 can also be toxic.  The dosage is the key!  I think when it comes to dog food there is too much of the "Sky is Falling".
 
[linkhttp://www.peteducation.com/article.cfm?cls=2&cat=1662&articleid=710]http://www.peteducation.com/article.cfm?cls=2&cat=1662&articleid=710[/link]

Wow Abbysdad,,,how interesting.
Even Vit C...I have read a few times (and have a big "Vitaman Freak" friend who keeps telling me) not to give your dog because they produce their own Vit C and therefore to give it to them would be too much. I know Vit C is water soluble..but I have read that.
Why is vitamin K added by some dog food companies?