Vit A, D, and K work together. Take some Vit A, not too much, get Vit D 60-80 ng/ml, and take enough Vit K2 (either MK4 or MK7) so uncarboxylated osteocalcin is low. (I hope that test will become more easily available eventually.) Some people have metabolic weaknesses that contribute to calcification, such as having elevated Lp(a), being Apo E 3/4 or 4/4 (relative intolerance of fats, where a low-carb diet is called-for), and eating so many carbs that LDL particle number is elevated with a high percentage of small LDL, which infiltrate the endothelium most easily. The T3 portion of thyroid hormone is proving to be vital to have optimized. Also, use fish oil, magnesium, and iodine.
I'm probably forgetting something.
Last but not least, Dr. William Davis of Track Your Plaque would say, Stop Eating Wheat! -- though that may have more to do with prevention than reversal :) Oh, and Exercise, of course!