Cutetonic® Ultra Fine Vitamin C 500mg 60 Capsules (L-Ascorbic Acid) – Suitable for Vegetarians & Vegans Cutetonic vitamin c supplements are perfect for complementing a healthy, balanced diet, whilst also supporting immune function. Vitamin c is one of the most widely used supplements with research suggesting that vitamin c can help to reduce the duration of illness. Use of vitamin c assists in supporting the immune function. Vitamin c is an antioxidant, and helps to protect cells against free radical damage. As exercise increases free radical production, vitamin c makes a good choice.