It has been a miserable season for the 28-year-old Vickery who has only recently returned to full fitness following a catalogue of injuries.
Vickery started England's 18-17 defeat to France last weekend and he looked like he would be automatic first choice for Andy Robinson's team, who take on Ireland next weekend at Lansdowne Road - a game England must win having lost twice in the tournament so far.
With Leicester's Julian White also sidelined Robinson does not have any tight head props left in his 30-man squad, forcing him to look at Matt Stevens and Duncan Bell and Northampton's Robbie Morris.
Gloucester director of rugby Nigel Melville said : "Phil has broken his radius which is the large bone in his forearm. He will go to hospital (on Saturday night) and have a plate put in it.
"I don't really know how it happened but Phil will definitely be out of action for at least six weeks.
"I feel very sorry for him as he has been in great shape. He really needed 80 minutes of rugby (on Saturday) and then this happened to him. Mentally it must be very hard for him."