Myth: Calcium is essential to prevent osteoporosis
How often does the public receive confusing messages from the health experts? One minute we are told one definite scientific fact only to be informed that this is no longer true. You’d be forgiven if you’ve developed healthy cynicism around these issues because the reality is that in many areas, science is conflicted and a researcher’s perspective, their own individual results and biases, along with a clouded view of statistics, leads to data about a particular scientific issue possibly being contradictory.
For many years, the debate has raged on around the place of calcium supplements for osteoporosis and general bone health. There have been recent suggestions from a variety of sources that calcium supplementation may not only have no place in osteoporosis management and fracture prevention, but also increase risk for heart attack.
So, taking the calcium story as one very good example of contradictory scientific information, a group from Auckland published a meta-analysis suggesting the regular ingestion of calcium supplements led to a 30% increase risk for heart attack. Firstly, to put this in perspective, this doesn’t mean that if you swallow calcium pills you have a one in three risk for a heart attack. It purely means that if you examine the cardiac risk profile of the study group and estimate (for example) that the particular demographic group in question has a 10 year risk for heart attack of 10%. Those who take oral calcium pills increased the risk up to 13%, which is a 30% increased relative risk. This makes the data somewhat less scary.
A recent study from the UK published in the journal “Bone and Mineral Research” followed 500,000 men and women age 40–70 and reviewed the relationship between calcium and/or vitamin D supplementation and the risk for cardiovascular events such as a heart attack. This study, contrary to the work from the Auckland group, found no increased risk of calcium supplementation, whatsoever. This was regardless of the intake of vitamin D.
So, although the potential for calcium supplements to cause harm is suggested, but, by no means definite, the major question is whether taking calcium supplements has any benefit at all? The answer here appears more straightforward and that is, no.
In 2014, a large meta-analysis involving 100 trials of calcium supplementation asked 2 major questions. Does calcium supplementation with or without vitamin D prevent or treat osteoporosis and secondly does it prevent bone fracture? The review showed minimal to no benefits in the vast majority of trials with the exception of elderly patients in a French nursing home trial where calcium supplementation appeared to afford a reasonable benefit for osteoporosis prevention and management.
So, with our current level of evidence suggesting no real benefits and a possible potential for harm, it’s best to avoid supplementing with oral calcium and seek your calcium from dietary sources.
Even then, there are some health professionals who maintain the evidence for dietary calcium as part of osteoporosis management has minimal compelling evidence to support its recommendations in this situation. The problem here is to prove the benefits from dietary calcium sources, such as dairy products, for the prevention and management of osteoporosis would require a very long term study in thousands of people which could only be observational as you cannot perform a randomised controlled clinical trial with a “placebo dairy group”. (The reality is that this is true for all lifestyle interventions as you cannot have placebo smoking, dietary, alcohol, exercise, sleep or stress groups).
So, where does this leave us with osteoporosis management? Firstly, osteoporosis occurs in many people as we age, women more so than men. There are many factors that are associated with increased risk apart from age which include genetics, lower body weight, smoking, alcohol, thyroid disease and a number of other factors.
The best non-pharmacological management is the following:
1) Exercise — This is easily the most important aspect of management for osteoporosis. The Walker suggested dose is 3 to 5 hours per week with two thirds cardio and one third resistance training such as weights, yoga or Pilates.
2) Avoid fizzy drinks. In the vast majority of soft drinks, regardless of whether they are sugar sweetened or artificially sweetened, is a chemical additive to induce the fizz, known as phosphoric acid. Some of the cleverer companies call this “food acid” to make it sound somewhat safer. Phosphoric Acid rips the calcium out of bones and should be avoided.
3) Calcium from dietary sources, not pills.
4) Vitamin D — the evidence that vitamin D prevents and manages osteoporosis is certainly not definitive but there is a clear link between low levels of vitamin D (it is estimated that around a third of the population is deficient) and increased risk for osteoporosis. So, 10 to 15 minutes in the sun during the non-burning times or a harmless supplement of D3 (between 1000 to 5000 I.U. daily, depending on blood levels) is the best way to combat vitamin D deficiency.
5) Vitamin K2 — the “new kid on the block” has a reasonable evidence base to demonstrate the removal of calcium from arteries, putting it back in the bones where it belongs. The best study of vitamin K2 followed 244 postmenopausal women with half receiving vitamin K2 180 µg daily for three years and the other half receiving placebo. This is demonstrated clear evidence for improving bone strength and arterial flexibility.
In conclusion, the long-held belief that calcium supplementation used to prevent & treat osteoporosis does not have strong scientific support with the potential for harm. Osteoporosis, especially when severe, may also require pharmaceutical therapy but as with all conditions, prevention is better than cure.
