Vitamin C, also known as Ascorbic Acid, is a water-soluble vitamin.
It is essential for normal body functioning. Humans must obtain vitamin C trough their diet. Other mammals have the opportunity to produce their own vitamin C supply.
Vitamin C is a vitamin found in various foods and sold as a dietary supplement. It is used to prevent and treat scurvy. Vitamin C is an essential nutrient involved in the repair of tissue and the enzymatic production of certain neurotransmitters.

Functions

Vitamin C is need for the growth and repair of tissues in all parts of your body. It helps the body make collagen, an important protein used to make skin, cartilage, tendons, ligaments, and blood vessels. Vitamin C is needed for healing wounds, and for repairing and maintaining bones and teeth. It also helps the body absorb iron from nonheme sources.

Rich Foods

1) Oranges 1 large: 82 mg (over 100% DV)
2) Red peppers half cup chopped, raw: 95 mg (over 100% DV)
3) Kale 1 cup: 80 mg (134% DV)
4) Brussels sprouts half cup cooked: 48 mg (80% DV) 
5) Broccoli half cup cooked: 51 mg (107% DV)
6) Strawberries half cup: 42 mg (70% DV) 
7) Grapefruit half cup: 43 mg (71% DV)
8) Guava 1 fruit: 125 mg (over 100% DV)
9) Kiwi 1 piece: 64 mg (33% DV)
10) Green peppers half cup chopped, raw: 60 mg (100% DV)
11) Mango 1 cup: 45.7 mg (76% DV)
12) Lemon
etc..

Overdose

Overdosing on vitamin C leads to:
Diarrhea
Nausea
Vomiting
Heartburn
Abdominal bloating and cramps
Headache
Insomnia
Kidneys stones

Deficiency

C
Symptoms of vitamin C deficiency includes: Dry skin, Splitting hair, Swelling and discoloration of your gums, Sudden and unexpected bleeding from your gums, Nosebleeds, Poor healing of wounds, Problems fighting infections.