The study, published in the Journal of Small Animal Practice looked at 76 cats who had been diagnosed with hyperthryoidism. They compared these cats to cats who had normal thyroid levels.
The cats with hyperthyroidism had significantly lower cobalamine (B12) levels.
This is an interesting study. We have known for a while now that cobalamine levels can be lowered in cats with inflammatory bowel disease, but it will be interesting to see how we use this information when treating hyperthyroid cats. I have noticed that many cats with hyperthryoidism have diarrhea, so maybe the low cobalamine levels are the culprit.
I will likely be running cobalamine blood levels in my newly diagnosed hyperthryoid patients and if low, supplement them with Vitamin B12.