I don't know where I got the idea of the D being "Vitamin D", but I talked myself out of getting what I probably really should be taking, for several reasons. There's alot of studies for it's effectiveness for tumors/cancer too. That was the liver pathway that was the worst for me on the liver detox pathways test too.
In 1986 Walaszek and co-workers demonstrated that taking D-Glucarate orally, in animals and humans, leads to a slow release of a substance that inhibits glucuronidase. Glucuronidase is an enzyme that thwarts the body’s efforts to rid itself of cancer causing substances known as carcinogens. Walaszek demonstrated that if you feed animals Glucarate, there is an increase in the level of a substance known as D-Glucaro-lactone, which inhibits glucuronidase.