Vitamin C Vitamin C is one of the most commonly supplemented vitamins; this is an essential nutrient that we must either obtain from diet or supplements. It is found only in the fruit and vegetables, and is highest in fresh, uncooked food, although it can only stay in the bloodstream for about 4 hours. As a powerful antioxidant, extra amounts are needed by those who smoke, drink alcohol, or are under a lot of stress. Illness and some medications will also affect our ability to absorb vitamin C. How will Vitamin C with Citrus Bioflavonoids help me? In this formula they are combined in a unique base containing 50mg each of lemon, orange & grapefruit bioflavonoids, hesperidin complex, rutin and rose hips extract. Vitamin C is a well-known antioxidant vitamin that contributes to the normal function of the immune and nervous systems and normal psychological function, and its antioxidant properties are used to protect cells against oxidative stress. Vitamin C also contributes to a reduction in tiredness and fatigue. This formula includes calcium and phosphorus, which are known for the maintenance of normal bones, teeth, and energy-yielding metabolism. Calcium also contributes to normal neurotransmission, muscle function, blood clotting, and the function of digestive enzymes.