The 102-Test veteran will miss the first three matches of the Blues' season before returning on March 18, the All Blacks said in a statement.
"It's a total break away from the routines of the game so that I can enjoy some downtime and chill out with my family before getting back into it in a few months' time," Mealamu was quoted as saying in a statement.
Mealamu has just returned from New Zealand's tour of the northern hemisphere at the end of a 2012 season disrupted by injury. He has the backing of his Auckland-based club while New Zealand Rugby Union (NZRU) chief executive Steve Tew called the extended leave period a sensible move by the 33-year-old.
"Keven has only just returned today from his off-shore rugby commitments, and it's entirely understandable that he will want to take a long break to spend more time with his family," Tew said.
"This is a sensible break for Keven, and one we hope will allow him to keep performing at that top level for a lot longer."