Best Naturals, Calcium Citrate, 1000 mg per Serving, 240 Tablets
Calcium bound to citric acid is a well-absorbed form of calcium. Citric acid is a naturally occurring organic acid that is able to efficiently bind three mineral molecules for every one of its own molecules. Studies have shown significantly more calcium is absorbed in the body from calcium citrate than from calcium carbonate. One study found patients with low hydrochloric acid levels absorbed an average of 10 times more calcium from citrate than from carbonate.