Here you go

Solution to fixing a Nitrogen deficiency

Avoid excessive ammonium nitrogen, which can interfere with other nutrients. Too much N delays flowering. Plants should be allowed to become N-deficient late in flowering for best flavor.
A goof solid N-P-K ratio will fix any nitrogen deficiency. Any chemical or organic fertilizers that have Nitrogen in them will fix a nitrogen deficiency., Peters all purpose plant food 20-20-20 is good, Miracle grow All purpose plant food, Miracle grow Tomato plant food, (Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) as well and blood meal! If you need to give your plants a quick solution to nitrogen and you want to use blood meal, I suggest making it into a tea for faster use, where blood meal is slow acting, but when made into a tea it works quicker! Other sources of nitrogen are dried blood, Cotton seed meal which is slow acting, Insect eating bat guano which is fast acting. Bone meal which is a gradual absorption when not made into a tea.( also excellent source of phosphorus). Fish Meal Or Fish Emulsion is a good source of nitrogen and is medium acting. Worm castings, which is gradual absorption. Seabird guano, All purpose Millennia Seabird guano, Orginal Seabird guano All Purpose, Crabshell ,which is slow absorption. Fox Farm Grow Big, which is fast acting. ( can bring down your ph as well)
Here are a list of things that help fix a Nitrogen Deficiency:

Chemical Nutrients

Advanced nutrients Grow (2-1-6)
Vita Grow (4-0-0),
BC Grow(1.2-3.2-6.5)
GH Flora Grow (2-1-6)
GH Maxi grow (10-5-14)
GH floraNova grow (7-4-10),
Dyna gro Grow (7-9-5)

Organic Nutrients

Dr. Hornby's Iguana Juice Grow (3-1-3)
Advanced Nutrients Mother Earth Grow (1.5-.75-1.5)
Earthjuice Grow (2-1-1),
Pure Blend Pro (3-1.5-4)
Bone Meal(0-10-0)
Blood Meal(12-0-0)
Fish Emulsion (5-1-1)
Seabird Guano (11-13-3)
Crab Shells(2.5-3.0-.5)
Pure Blend Grow (0.4-.01-.5)
Marine Cuisine (10-7-7)
MaxiCrop Seaweed (1-0-3)
Super Tea (5-5-1)
Mexican Bat Guano (10-2-0)
Sea Island Jamaican Bat Guano (1-10-0)
Kelp Meal (1-0-2)
Seaweed Plus Iron
Neptune's Harvest (2-4-0.5)
Alaska Start-Up(2-1-2)
Bio-Grow (1.8-0.1-6.6)
Age old Grow (12-6-6)
AGE Old Kelp (.30-.25-.15)
Neptune's Harvest (2-4-1)
Maxicrop Seweed(.1-0-1)
METANATURALS Organic grow (3-3-3)
METANATURALS Organic nitrogen (16-0-0)

So adding anyone of these above should fix up your nitrogen deficiency! Nitrogen deficient plants usually recover in about a week, affected leaves will not recover.