Sitrus Sr is a food supplement that contains a vitamin c in a sustained release form with added Zinc and Selenium . Absorption of vitamin c is greater when several individual doses are taken throughout the day rather than one large 'immediate release'' dose. Sitrus -SR releases less than 20mg of vitamin C at a time and hence ensures round the clock levels of Vitamin C. -Contributes to the normal function of the immune system -Contributes to the protection of cells from oxidative stress -Vitamin C contributes to the reduction of tiredness and fatigue -Vitamin C contributes to normal collagen formation for the normal function of blood vessels -Zinc is responsible for a number of different functions of human body and it helps stimulate the activity of 100 different enzymes. Selenium has a protective role in thyroid and systemic inflammatory disorders. Selenium is protective against cancer, heart diseases and mental decline.