The daily requirement of vitamin C is: 

0-6 months: 40mg, 7-12 months: 50mg, 1-3 years: 15mg, 4-8 years: 25mg, 9-13 years:45mg, 14-18 years: male: 75 mg, Female 65 mg, Pregnancy: 80 mg, Lactation: 115 mg, 19 years+: Male: 90 mg, Female: 75 mg, Pregnancy: 85mg, Lactation: 12 mg. 

Consuming more than 1000mg daily could cause diarrhoea, flatulence and stomach pain. 

Citrus fruit, such as oranges and orange juice, peppers, strawberries, blackcurrants, broccoli, Brussels, sprouts, and potatoes. 

Smokers require 35mg/day more than the nonsmokers. 

Smokers and passive smokers, people with malabsorption and certain chronic diseases, infants fed evaporated or boiled milk and individuals with limited food variety are at a higher risk of vitamin C deficiency. 

According to epidemiological data, eating more fruits and vegetables is: 

linked to a lower risk of developing most cancers, possibly in part because of the high vitamin C content of these foods is associated with a lesser risk of cardiovascular disease, 

It was also found that high plasma vitamin C concentrations were associated with a lesser risk of stroke, 

Another cohort study found adults aged 55 years or older who had a high dietary intake of vitamins and other nutrients like vitamin A, Zinc, and E had a lower risk of age-related eye problems.