The Nation's Health

Calcium: What role calcium supplements?

A frequent question in the Track Your Plaque program is whether taking calcium supplements to reduce risk for osteoporosis adds to calcium in arteries and raises CT heart scan scores.

No, calcium supplementation does not add to coronary calcium. Thankfully, there is some wisdom to calcium metabolism. Calcium deposition or resorption is under independent local control in bone, as it is in the artery wall. Taking calcium has no effect on calcium deposition in your coronary arteries.

However, there's a lot more to it. Taking calcium has only a modest effect on bone health. Most women can only hope to slow or stop calcium loss from bone by taking calcium supplements. Calcium supplements do not increase bone calcium. The reason why calcium supplementation works at all is, when calcium is absorbed into the blood, it provides a feedback signal to the parathyroid gland to shut down parathyroid hormone production, the hormone responsible for extracting calcium from bone. But the calcium itself does not end up deposited in bone.

Likewise, calcium supplements have essentially no effect on the artery wall. But vitamin D controls calcium absorption and, curiously, appears to exert a dramatic effect on calcium depostion in coronary arteries. In fact, I would credit vitamin D as among the most important factors in regulating arterial health that I've encountered in a long time.

Thus, bone health and arterial health do indeed intersect via calcium, but not through calcium supplements. Instead, the control exerted by vitamin D connects the seemingly unconnected processes.

Vitamin K2 provides another unexpected juxtaposition of the two processes. Deficiency of K2, which is proving to be a lot more common than previously thought, permits an enzyme in bone to exert unrestrained calcium extraction . Deficiency of K2 in artery walls allow another enzyme to deposit calcium and grow plaque without restraint. Yet another intersection between bone health and coronary health that involves calcium, but as a passive participant.

Stay tuned for a comprehensive Track Your Plaque Special Report on these topics coming in the next couple of weeks. I'm very excited about the emerging appreciation of calcium as an active ingredient in plaque, not a dumb, passive marker as previously thought. Vitamins D3 and K2 are among the keys to this phenomenon.