"Companion nutrients" refers to certain vitamins, minerals, or substances that work together to enhance each other's benefits in our bodies. They support and complement each other, helping to maximize their effectiveness and absorption.
Full definition
It is also important to understand that ensuring a proper supply
of companion nutrients that support vitamin D activity can enhance some of the beneficial roles of vitamin D in the body.
Maybe glucosamine has
companion nutrients as well (besides chondroitin)-- other elements the body needs in order to absorb glucosamine and deliver it to the dermis and other connective tissue.
Mother Nature tends to build all
those companion nutrients directly into the food, even before we «discover» them and assign them a name.
The refining and processing of both sugar and HFCS while stripping away all
the companion nutrients and enzymes that normally accompany those sugar sources can spell disaster for dogs more quickly than for humans.