Vitamin C supplements are known for aiding the immune system in fighting against colds and other sicknesses, but supplements are often highly acidic, making it hard for sensitive individuals to digest them comfortably. Buffered vitamin C, which is vitamin C buffered with sodium, magnesium, calcium, or potassium ascorbate, is often gentler on the body, and can be taken without stomach upset and provides a longer-lasting effect. In her book Author Maureen Keane states that this slower absorption leads to both better “quality control” and gives “longer-lasting benefits” Buffered vitamin C allows the body to benefit from one dose for up to sixteen hours.