A scale showing typical weight, height and caloric intake for the ages and gender used to establish the RDA can also be checked. If you dramatically differ from the scale based upon your age and gender, then you should adjust your nutrient vitamin and mineral intake accordingly. Vitamin C is stable to air when pure and dry, however when in aqueous solution and in natural products such as plants and fruits, it degrades rapidly by oxidation on exposure to air and light. It is not affected by light but is destroyed by excessive heat especially in an alkaline solution. Forms stable metal salts.
Good sources are citrus fruits, hip berries, acerola, and fresh tea leaves.
Additional sources are from juices, tomatoes, and other fruits and vegetables. Though many foods contain vitamin C, the quantities are rather low and unstable to storage and cooking. Eggs, meat and fish are rather poor sources, as is milk after pasteurization. Dried cereal grains and the seeds of legumes are devoid of vitamin C unless sprouting. The best way to obtain high amounts of vitamin C is through health supplements.