HealthAid Vitamin C is buffered with Rosehip and Aceroal, so it is highly bioavailable and gentle on the stomach. Alongside a healthy immune system, Vitamin C also contributes to the protection of cells from oxidative damage.? Too much Vitamin C may cause an upset stomach for sensitive individuals. Vitamin C from HealthAid? is specially formulated with Rosehip and Acerola to give a buffered tablet that does not irritate the stomach and is rapidly absorbed.