Pure Encapsulations Buffered Ascorbic Acid CapsulesPure Encapsulations Buffered Ascorbic Acid Capsules If you have a sensitive stomach, getting enough vitamin C from acidic foods can be a little tricky. Since many vitamin C sources are citrus fruits or other tart foods, they may be harder to tolerate. Good news: Pure Encapsulations Buffered Ascorbic Acid was made to give you the vitamin C you need in a form thats gentler on the stomach!* This buffered ascorbic acid combines ascorbate from magnesium,