The 21-year-old signed from non-league Great Yarmouth in the summer of 2011 having impressed the Daggers while on trial.
Last season saw Reed suffer with both injury and illness but he has proved his worth this term, starting eight of the club's last nine games to take his total number of appearances to 22.
Manager John Still said: "This is Jake's second year with us and he's started eight league games now and he's worked really hard.
"We are all really pleased with the progress he has made and of course I am delighted he has extended his time here. Hopefully between now and the start of next season we will see him push on even further."
- Sports & Recreation