New (ish) from: Bragg RR, Freeman LM, Fascetti AJ, Yu Z, 2009. Composition, disintegrative properties and labeling compliance of commercially available taurine and carnitine dietary supplements. JAVMA 234:209-213
Dietary supplements still have a bad rap with nutritionists, who worry about whether they will be effective or harmful. Quality control is the major sticking point, as dietary supplements - especially for animals - lack consistent regulatory oversight to ensure the companies are putting what they say they do in the bottles. Some frightening papers about probiotics come to mind - one published in 2002 showed that NO veterinary products had labels that accurately reflected their contents. One of those products was a very popular probiotic product used by most professional dog handlers and breeders.
So one of the authors of this paper is a nutritionist married to a cardiologist, and her interest was in 2 nutraceuticals used in certain forms of heart disease - carnitine and taurine.
To give you the punchline, 10 of 11 taurine products contained within 10% of the taurine contents claimed on their labels, while 3 of 11 were within 5% of the label claim. For carnitine products, 6/10 were within 5% of the label claim and all fell within 10% of the label claim. So the only product that was significantly different from what the label claimed was Jarrow Formulas Taurine 1000.
Could have been a bad lot, a bad day or an inaccurate analysis, but it DOES serve as a heads up - that's a veteran company that many trust, and it would serve us well to stay in touch with the companies we trust, showing concern about results like this.
These were all products for human consumption, as most of the veterinary companies concentrate on making formulas. I wonder if the result would have been different had these companies been members of the National Animal Supplement Council?