L-Arginine ( or simply called Arginine), it's food sources, nitric acid and blood vessels

The following is extracted from:

http://www.m.webmd.com/a-to-z-guides/arginine-heart-benefits-and-side-effects

L-Arginine ( or simply called Arginine)

Deficiencies of arginine are rare. It's abundant in many different types of foods, and your body can also make it. Arginine-rich foods include red meat, fish, poultry, wheat germ, grains, nuts and seeds, and dairy products. 

Arginine, also known as L-arginine, is involved in a number of different functions in the body. They include

Wound healing

Helping the kidneys remove waste products from the body

Maintaining immune and hormone function

As a natural dietary supplement, arginine has garnered particular attention for its possible heart benefits.

What Are Arginine's Heart Benefits?

In the body, the amino acid arginine changes into nitric oxide (NO). Nitric oxide is a powerful neurotransmitter that helps blood vessels relax and also improves circulation.