Osteoporosis

Updated 02 July 2015

Calcium alone won’t prevent osteoporosis

We need calcium to build strong bones and prevent osteoporosis, but we also need to make sure this important mineral is properly absorbed, that we don't overdose and that we get enough of the other bone-building nutrients.

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Our skeleton is the frame around which our body is structured. We need bones to keep everything together and to protect our vital organs. Many of our strongest muscles are also connected to our bones.

Strength and flexibility

We seldom give our bones a second thought, but as we grow older they may become weak and brittle and end up fracturing at the slightest provocation. This is called osteoporosis. Osteoporosis occurs when the formation of new bone doesn’t keep up with the erosion of old bone tissue.

Read: how to prevent osteoporosis

Osteoporosis affects all people, but especially older women past menopause are at risk.

According to eMedicineHealth bone is made mostly of collagen, a protein that is woven into a flexible framework.

Bone also contains a large amount of calcium, which, in combination with collagen, gives the bone its strength and flexibility.

Other important minerals in bones are potassium, magnesium, manganese, silica, iron, zinc, selenium, chromium, boron, phosphorus and sulphur.

It is certainly true that bone consists largely of calcium and that 98% of the body’s total calcium resides in our bones. While loss of calcium from the bones and lack of calcium in the diet to build new bone tissue definitely contribute to osteoporosis, there’s more to it than that.

Are we overdosing on calcium supplements?

Men and especially post-menopausal women are told they can’t go wrong by consuming dairy products and take calcium supplements on a daily basis. Calcium is also added to foodstuffs from margarine to orange juice. The idea that this could be misguided advice and might actually be bad for us is regarded as near blasphemy.

Read: Dairy diary: the lowdown and the heads-up

However, a study saying just that was published in JAMA Internal Medicine in 2013. The study basically found that men who consumed more than 1,500mg of calcium a day had an increased risk for cardiovascular disease. Other research has found that too much calcium is related to a small risk of kidney stones.

Even more surprising are the findings of a 2013 study by the U.S. Preventive Services Task Force (USPSTF), a group of experts that makes recommendations about preventive health care. The study came to the conclusion that “... there is good evidence that daily supplementation with 400 IU of vitamin D3 and 1000 mg of calcium has no effect on the incidence of fractures in postmenopausal women.”

It’s actually not that difficult to see that there’s something wrong with the idea that extra calcium protects us against osteoporosis. Despite the fact that the average American consumes 600 pounds of dairy per year, their osteoporosis rates are among the highest in the world.

So, what are we doing wrong and why doesn’t this theory work? If our bones consist largely of calcium and tend to break because of a lack thereof, it surely makes sense that consuming more calcium would prevent the osteoporosis.

Absorbing the calcium

Could it be that all of the calcium we are ingesting isn’t finding its way to our bones? And could consuming too much calcium contribute to an abnormal amount of calcium in the blood that ends up in parts of the body where it doesn’t belong?

According to Healthline, when your bloodstream fails to get rid of excess calcium, it can end up in the arteries of the heart, brain (cranial calcification), breasts and kidneys (as a part of kidney stones or calcium deposits in the kidneys).

Read: The lowdown on kidney stones

So, what can we do to ensure that the calcium we consume reaches our bones and teeth?

Let’s have a look at some other nutrients involved in the building of strong bones:

- Vitamin D plays a pivotal role in bone building; it allows the body to absorb calcium, and to maintain the proper balance of calcium and phosphorus. If you are not getting the right amount of vitamin D with your calcium, your body will not absorb it properly.

That’s the reason why vitamin D is often added to milk and other dairy products. Vitamin D can be created naturally in the skin when it is exposed to sunlight, but many people do not produce enough vitamin D or get enough from food.

Good dietary sources of vitamin D include fatty fish such as salmon, mackerel, tuna and sardines, fish oils, butter, egg yolks, liver, and fortified foods such as breakfast cereals, milk, margarine and orange juice.

- Magnesium is necessary for many activities in the body. Magnesium stimulates the hormone calcitonin, which helps to preserve bone structure by drawing calcium out of the blood and soft tissues back into the bones. Another lesser known fact is that that magnesium is necessary to convert vitamin D into its active form so that it can turn on calcium absorption.

Cocoa, nuts, pumpkin, sunflower and other seeds and grains are foods rich in magnsium.

- Boron is important in preventing calcium loss, as it improves calcium absorption and reduces the amount of calcium excreted in the urine. Boron is found in raisins, prunes and nuts as well as chickpeas, avocado, and bananas. You should get 3m g a day. Those following a low-carb diet should ensure they eat enough fresh vegetables if they avoid the main sources of boron. 

- Phosphorus. According to WebMD calcium needs phosphorus to maximize its bone-strengthening benefits, and taking calcium supplements without enough phosphorus could be a waste of money. More than half of all bone is made from phosphate, and small amounts are also used in the body to maintain tissues and fluids.

And what’s more, taking large amounts of supplemental calcium can interfere with phosphorus absorption because calcium can bind phosphorus, making it unavailable to the body.

Dairy products, liver, seafood, fatty fish and meat are rich in phosphorus.

- Vitamin K has only recently been identified as an important nutrient in bone health. A number of studies have indicated that low vitamin K levels are associated with a higher risk for osteoporosis and bone fractures, and that supplementation with vitamin K increases bone mass and mineralisation of the bone matrix.

Vitamin K1 is the most common form of vitamin K. However, vitamin K2 is the most important. It has recently been found that menaquinone-7 (MK7), a long chain vitamin K2 molecule, is the form that protects against osteoporosis and reduces the risk of bone fractures.

Vitamin K1 is found especially in green leafy vegetables, while liver and fermented foods are the best sources of  vitamin K2. Natto, a Japanese food made from fermented soybeans, is the richest source of vitamin K2.

Prevention is better than cure

So, don’t be a victim of osteoporosis – with the right nutrition and supplements this bone wasting disease is entirely preventable. And if you're taking calcium, see that it's no more than 1000mg per day, and 1200mg for those over 70 or post-menopausal women where a drop in oestrogen levels cause osteoporosis. Always try to get these from food sources rather than supplements.

Read more:

Post-menopausal women unaware of osteoporosis risk

Vitamin K: The new bone nutrient

Vitamin K under trial

Calcium calculator

Image: Strong bones from Shutterstock

 

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Healthy Bones

Tereza is the CEO of the National Osteoporosis Foundation and worked as a Nursing Sister in the field of Osteoporosis for 18 years prior to her appointment with the Foundation. She used to be the Educational Officer for the Foundation and co-wrote the patient brochure on Osteoporosis. Read more

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