Monday, April 28, 2014

Should Physicians Stop Prescribing Calcium Supplements?

Calcium supplements should be a thing of the past says Ian R Reid, MD Faculty of Medical and Health Sciences, University of Auckland, Auckland New Zealand.
February, 2014 (Journal of Bone Metabolism)

Reid says use of calcium supplements came about when there were no other effective interventions for the prevention of osteoporosis and was focused on the belief that increasing calcium intake would increase bone formation. Our current understanding of the biology of bone suggests this does not occur though calcium does act as a weak antiresorptive. Thus, it slows postmenopausal bone loss but, despite this, recent meta-analysis suggests no significant prevention of fractures. In sum, there is little substantive evidence of benefit to bone health from the use of calcium supplements. Against this needs to be balanced the likelihood that calcium supplement use increases cardiovascular events, kidney stones, and gastrointestinal symptoms, and admissions to the hospital with acute gastrointestinal problems.

This is another example of hypocognition (acquiring new information but having no basic framework of knowledge in which to place it) in the field of health care. Calcium has many uses in the body. It is necessary for muscle activity and nerve function. Bone is merely the repository for calcium. It acts as a storage site in the body, accepting and releasing calcium as it is needed by the body.

By the way, biphosphanates, like Fosamax and Boniva, the current accepted method of treatment for osteoporosis, increase the rate of hip fracture, rather than reduce it.

The increased risk of cardiovascular events associated with calcium supplementation is urban legend. When plaque accumulates in the walls of arteries, it can loosen over time and become “vulnerable plaque”. The body then deposits calcium into the plaque to strengthen the adhesion to the artery wall. We can measure the calcium content of artery plaque with a high speed CT scan. This gives a “calcium score” that rates your risk of cardiovascular accident. The higher the calcium content, the more vulnerable plaque present. However, the calcium is actually protecting the body, not putting it at risk.

There are only two types of calcification in the body. The first is dystrophic calcification. This is calcium deposition secondary to an injury. Calcium deposit in a torn bursal sac in the shoulder is a common example. So is the calcium in vulnerable plaque. The second form of calcification is metastrophic calcification. This is calcium deposition secondary to a metabolic disorder. Kidney stones are commonly caused by a variety of metabolic disorders. These deposits have nothing to do with calcium intake. In fact, your body with actually take the calcium from bone to create the deposits if either of these processes is active.

The primary purpose of calcium is to buffer the blood stream. The acid-base balance of the blood is very tightly controlled with a pH of 7.36 to 7.44. The body will move calcium in and out of bone to help keep the pH tightly controlled.

Calcium also fills binding sites along the course of the nervous system. When a nerve fires, (depolarizes) calcium is displaced in sequence as the impulse travels along the nerve fiber. If insufficient calcium is present, the nerve will fire spontaneously. This often results in cramping if the nerve innervates muscle.

Calcium is a carrier molecule in the blood stream, transporting other minerals to tissue sites in the body.

Although calcium’s role in bone strength is limited, it is an important mineral in many body functions. Few women get adequate calcium in the diet and must supplement. Men who exercise on a regular basis also need to supplement their diet with calcium.

If you suffer from leg cramps, especially at night, you are probably deficient in calcium. Try taking 500mg of elemental calcium, at night, just before bedtime.