Agent Orange was but one of the many defoliants used in Vietnam, there were different colors for different things.
The VA for years denied the claimes to Vietnam Veterans because the Vietnam Veterans sort of stuck to the name Agent Orange for all their ills, but it was the defoliants together which caused the trouble in Veterans.
All the VA had to do for years was prove that Agent Orange did not cause at least some of the problems which were being attributed to Agent Orange exposure, once the terminology was changed the VA really had no leg to stand on legally.
Defoliants used in Vietnam cause many problems in Veterans, the defoliants got into the Water Table, so, defoliants also got into the food supply.
Vietnam Veterans are pretty much covered Service Connection wise for I believe anything wrong (really wrong, as in bad things to have) from the neck down, last I heard those with Brain Tumors could still not Service Connect under the defoliants used in Vietnam, but a number of Vietnam Veterans with such problems were pushing a case not very long ago, so it may be bumper to bumper now.
Sadly, many were lost before any benefits could be paid to the Service Member or Surviving Spouse and or Dependent Children.