Natures Aid Time Release Vitamin C 1000mg with added Citrus Bioflavonoids Indications Vitamin C supplementaton is not advisable for people who sufer from renal stones. Ingredients Vitamin C (as Ascorbic Acid), Di-Calcium Phosphate, Hydroxypropylmethylcellulose, Microcrystalline Cellulose, Citrus Bioflavonoids, Anticaking Agents (Vegetable Source Magnesium Stearate, Silicon Dioxide).