Essential Fatty Acids and Vitamin E

Question:

Hello:
I recently purchased the EFA for my cats.  I have been giving it to them without any problem other than their dislike for its taste.  However, I just recently read that EFA can cause a Vitamin E deficiency and coincidentally, my one cat had blood work which indicated an elevated CK enzyme.  She had x-rays which confirmed her heart is not enlarged, as an elevated CK enzyme can sometimes be indicative of.  Upon further research I came across some information that indicated an elevated CK enzyme can be attributed to a vitamin E deficiency.  I'm wondering your thoughts as to whether or not there might be a connection to the EFA.  She has been on it for well over a month.
Thank you in advance for any insight you may provide.
Kimberly K.

Response:

Hello Kimberly,
Thank you for your inquiry to Holistic Pet Info. There are several research papers that show high intake of EFA’s (also known as PUFA) in the diet can cause a vitamin E deficiency. The need for vitamin E in the diet is influenced by dietary content. The requirement increases with increasing levels of EFA, oxidizing agents, vitamin A, carotenoids and trace minerals and decreases with increasing levels of fat-soluble antioxidants, sulfur-containing amino acids and selenium (1).
The National Research Council (2) recommends that moderate to low-fat diets for growing cats should contain 30 IU of vitamin E per kg diet with a three- to fourfold increase in dietary vitamin E if the diet contains a high level of PUFAs. AAFCO (3) recommends that 10 IU of vitamin E should be added per gram of added fish oil per kg diet. However, the quality of fish oil used in the formulation of diets for cats is likely to affect the vitamin E requirements, and lower-quality fish oil will most likely increase in vivo oxidation in cats, thereby increasing vitamin E requirements. Estimates of vitamin E requirements in cats vary, therefore, depending on the quality of fish oil used. One study shows that when a high-quality fish oil is used, the dietary vitamin E requirement of adult cats fed high dietary levels of PUFAs from fish oil is <5 IU per gram of added fish oil per kg diet.
Most of the studies I have found spanned a time frame of 20 -24 weeks. If you are supplementing your cats’ diets with the Super EPA by Thorne, the dosage does not appear to be high enough to have and effect on Vit E. BUT, since there is no apparent cardiac connection at this time to the elevated CK, I would recommend discontinuing the EPA. If you would like to continue the EPA supplementing with 5 IU vitamin E should maintain the proper levels for your cat. I would recommend rechecking the CK level in the month or two; it can also be simply elevated from traumatic venipuncture. I’ve listed the sources of my information. Best of luck.
Sincerely,
Colleen Smith DVM, CVA

1. Hand, Thatcher, Remillard, Roudebush, (4th Edition) Small Animal Clinical Nutrion, pg 86
2. NRC. National Research Council (1986) The Nutrient Requirements of Cats, rev. ed. 1986 National Academy Press Washington, DC.
3. AAFCO (2000) 2000 Official Publication of the Association of American Feed Control Officials Atlanta, GA.
Colleen Smith DVM, CVA