Vitamin C as mineral ascorbates for sensitive individuals. Buffered ascorbic acid combines calcium ascorbate, magnesium ascorbate, and potassium ascorbate to create a neutral pH vitamin C. This special form of ascorbic acid lessens possible gastric irritation in sensitive individuals. • Vitamin C for sensitive individuals • Buffered ascorbic acid combines calcium ascorbate, magnesium ascorbate, and potassium ascorbate to create a neutral pH vitamin C.* • This special form of ascorbic acid lessens possible gastric irritation in sensitive individuals.*