Bluebonnet Nutrition - Buffered Chelated Magnesium - 60 Vegetable Capsule(s) Bluebonnet Nutrition Buffered Chelated Magnesium provides magnesium bisglycinate chelate buffered with magnesium oxide to increase the pH (alkalinity) of the formula making it more gentle on the digestive tract and easier to absorb. This supplement comes in easy-to-swallow vegetable capsules for maximum assimilation and absorption. Magnesium helps support bone and heart health.