Calcium Supplements Won’t Harm the Heart

Over the past decade, a number of studies have raised questions about whether calcium supplements might contribute to heart disease or stroke. Just this month, a study of U.S. adults found that supplement users were more likely than nonusers to have plaque buildup in their heart arteries. (Calcium is a component of artery-clogging “plaques.”)

But a new research review, commissioned by the National Osteoporosis Foundation (NOF), has come to a different conclusion. On balance, the review found, the evidence doesn’t support a connection between calcium supplements and heart disease or stoke.

As long as people don’t go overboard, calcium supplements should be considered “safe from a cardiovascular standpoint,” say the guidelines from the NOF and the American Society for Preventive Cardiology. Getting calcium from foods such as milk, yogurt and tofu is still preferred, the groups say.

The guidelines and evidence review were published online Oct. 24 in the Annals of Internal Medicine.

The researchers analyzed 31 studies. Four of them were clinical trials, where older adults (mostly women) were randomly assigned to take calcium, with or without vitamin D.

None of those trials showed that supplement users had higher risks of heart disease, stroke or death than participants given placebo pills, the review found.

The rest of the studies the Tufts team analyzed were observational: They looked at the relationship between people’s calcium intake, from diet or supplements, and their risk of heart disease or stroke. Again, the researchers found the studies showed no consistent connection between higher calcium intake and higher cardiovascular risks.

Wisdom Wednesday: Homocysteine

Homocysteine is an amino acid, one of the building blocks for protein. However, homocysteine is not found in the diet. Rather it is manufactured in the body from another amino acid methionine.

Methionine is one of nine essential amino acids that cannot be synthesized in the body and must be in the diet. Methionine is found in most proteins – red meat, turkey, chicken, fish, soy, many cheeses, and yogurt.

When homocysteine is created it is an intermediate metabolite. Vitamin B6 then converts it to cysteine or vitamin B12 and folic acid convert it back to methionine. However, deficiencies of these vitamins or other co-factors can allow homocysteine to accumulate in the blood stream.

In normal metabolism, when damage occurs to an artery wall, a little C-reactive protein (CRP) is created. This stimulates the homocysteine to combine with LDL (low density lipoprotein) and creates a patch over the damaged area of the artery. If, over time, the plaque begins to come loose, the body sends calcium into the plaque to secure it to the artery wall.

In abnormal metabolism (pathology), any of these factors that elevate can allow this repair process to run wild creating atherosclerosis and heart disease. Unfortunately, the first factor discovered in this process was LDL cholesterol. So it was labeled as “bad” and statin drugs were developed to lower the LDL and total cholesterol.

The statin drugs actually do work (a little bit) but they do so because they lower the CRP, not because they lower the LDL cholesterol. In fact, the data never supported the claim that high cholesterol is associated with coronary artery disease. Over half of patients suffering their first heart attack have normal or even low cholesterol.

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.

MY TAKE:
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.

THE BOTTOM LINE:
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.