This may be an on-going post as I acquire all the info I can on it so check back, please.
From the net:
B complex:
B complex is a balanced form of vitamin B supplementation; which is the only way B vitamins should be given, unless specifically instructed to give one of the B vitamins by your veterinarian. B vitamins are cofactors for a number of important biological processes. They are important in maintaining a positive environment for neural regenerative efforts. In addition, they are water soluble so that any excess is merely eliminated in the urine. I recommend that all dogs receive B complex supplements twice a day. For small dogs, use the regular B complex. For medium size dogs, use high potency B complex (B 50s). For large dogs, use high potency stress formula B complex (B 100s).
This 1st thread is about the need for Vitamin B1---- Pets and Vitamin B1, Thiamine - Is There Really a Need?
And here is a link on B12: B12 for Dogs | eHow.com
Here is a good link about all the B vitamins and what they are good for:Dog Vitamins : The B Complex Vitamins
This is so informative about the B vitamins and other vitamins and how they can help treat some diseases--I had to change the title of my post!!--
Dog Tip: Dog Tip: Vitamins
I also found this and since I am talking about a vitamin--Felt I should add this as a precaution about some vitamins--(and B6 is mentioned although I don't know why---May be because it is listed as if you were only giving that one B vitamin and the only way you should give B vitamins is in a complex form (the correct ratio of the dif. B vitamins together) Of course if your dog is needing a certain B vitamin to correct a 'life threatening' condition--You would consult a vet (although most vets admit they don't know much about the use of vitamins) You would want a vet/dog nutritionist specializing in this. And your dog would only be on a specific B vitamin for the necessary time to be on it as too long would upset the ratio of B vitamins! I may have an answer about the B6 before I complete this post! ----- Here is the link to another article on vitamins and it does say B6 is nontoxic. This article is done by 2 vets and are well known (from my state-WI.)--->
Water Soluble Vitamins - Vitamin C & Vitamin B Complex in Dogs And here is the other link on toxicity---->
How to Recognize and Treat Vitamin Toxicity in Dogs | eHow.com
I think I commented on this elsewhere in this forum but here it is again---Vitamin B will prob. make your pet pee bright yellow--This is nothing to worry about--Lol, if you take Vitamin B yourself--you will prob. notice the same thing--It is just the flushing out of the nonharmful B vitamins you don't need. On other hand if you don't see the bright yellow urine--May prove you really needed all the B vitamins and they are being used!!
Another thing to be aware of---B vitamins are destroyed by heat/cooking so if you cook for your dog or heat it up for some reason--most of the vitamin B is gone. Need to supplement??
As far as commercial dog food---When are the vitamins added If they add at all---hopefully not before all that heat they use to process the dog food!! If they don't add any at all and if not after heat processing if they do add--There is hardly any (if any) B vitamins (and some other vitamins gone too!) there. Might be interesting to call your dog food company and ask about all this!