OsteoPrime

Calcium is important-more than 99% of the body's calcium is found in the bones and teeth. But the body also needs vitamin D to properly use calcium and phosphorus. Magnesium activates enzymes that help form new calcium crystals. Vitamin K aids the osteocalcin production, the supporting structure on which calcium crystallizes in bone. Manganese aids bone mineralization and connective tissue synthesis. Studies show zinc, strontium, vitamin B6, vitamin C, silicon, copper, and boron also help form the connective structures in bone.

OsteoPrime, formulated by Jonathan Wright, M.D., and Alan Gaby, M.D., provides a balanced combination of these important nutrients to support and maintain healthy bones.

• Calcium carbonate is the form of calcium found in chalk, Tums, and many inexpensive supplements.  Its advantages?  It's cheap, and you can fit a lot of it in a pill.  It's disadvantages?  As an antacid, it may compromise digestion, potentially leading to a number of problems, not the least of which is constipation.  Also we need adequete stomach acid to absorb it.  If taken on an empty stomach, or by someone using acid-blocking medications, it will absorb poorly.
• Calcium citrate is considered a more "premium" form of calcium.  You can fit less of it in a single pill than you can calcium carbonate, but it absorbs better and does not impair digestion.  Although less well known, calcium lactate, gluconate, aspartate, malate, and chelate are all probably as good.
• Calcium hydroxyappatite (MCHA) is very absorbable and fairly economical.  It is highly recommended, but it is derived from cow bones, so not suitable for vegetarians.