Musculosceletal system

Vitamin D and magnesium protect bones from osteoporosis

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Everybody knows by now that calcium is one of the most important building blocks of our bones and teeth. Nonetheless, our bones are made up of many more components other than calcium. A very important one is magnesium and often people have a deficiency of it. In order that calcium can reach the bones in the first place, vitamin D is indispensable.

Both vital substances are responsible for calcium's absorption with the food and its incorporation into our bones – if they are not available, our locomotor system cannot function well. For optimal calcium supply as well as healthy bones and joints, calcium should always be purposefully taken combined with magnesium and vitamin D. Thus, a diet that includes foods containing vitamin D and magnesium helps to counteract deficiency of these important nutrients. Also beneficial is taking vitamin D-rich medications with the respective indication of preventing or alleviating osteoporosis.

What is osteoporosis?

Osteoporosis or bone loss is a disease characterized by the decrease of bone density and the tendency of bones to fracture easily. It manifests itself when the ratio of bone synthesis to resorption is shifted towards resorption, when bone formation slows down, for example, and therefore bone destruction becomes more prevalent. Both processes are part of regular bone remodeling, in which old bone tissue is continuously broken down and rebuilt. As a result of this, every seven to ten years the entire skeleton of a person is rebuilt. The hormones estrogen and androgen protect bones from increased mineral loss. With menopause, however, women's estrogen level decreases – making older women especially more prone to osteoporosis, contrary to men of the same age. About 95 percent of cases are primary osteoporosis. On the other hand, diabetic patients are especially affected by secondary osteoporosis, which occurs as a consequence of other diseases and also patients who have taken medications containing cortisone or those suffering from hyperthyroidism are affected. Osteoporosis especially affects the vertebral bodies and the femoral neck because first of all, they are quite fragile and secondly, they have to carry a lot of weight. The other bones of the skeleton are also more prone to fractures.

Magnesium deficiency and vitamin D deficiency can worsen osteoporosis

If the two biofactors vitamin D and magnesium, that are essential for bone synthesis, are not available, the course of osteoporosis can intensify. According to recent findings, magnesium is also credited with stabilizing functions in bone building. If there is no stabilizing magnesium during bone synthesis, this also decreases bone density. The term "osteoporosis" already indicates a lack of calcium in the bones – but not necessarily in other parts of the body. Calcium is taken out from the skeleton and reaches the blood in this manner. This is where a purposeful magnesium- and vitamin D-rich diet can help to bring calcium back to where it belongs. Regular exercise also helps bone strengthening by promoting its synthesis. In addition, movement also ensures muscle strengthening; flabby and weakening muscles have a negative impact on bone mass. Even regular walks, dancing or a little bit of gymnastics help to maintain bone density – while also being a lot of fun!

Why is vitamin D important for our bone structure?

Vitamin D is in charge of many important tasks in our body. It is, for example, an indispensable biofactor for the proper functioning of our immune system! Another main task of vitamin D lies in regulating calcium in our body, indicated also by its scientific name of "cholecalciferol". It controls the absorption and utilization of calcium from the diet. If there is too little vitamin D available, not enough calcium reaches the blood through the intestinal walls and the calcium level decreases – regardless of the calcium quantity supplied with the food. Although calcium in high doses can also reach the blood passively (without the help of vitamin D), this occurs only to a negligible extent. With babies and toddlers, in particular, this can become critical because they must incorporate a lot of calcium into their growing bones. Therefore, vitamin D is often administered to them as a preventive measure against rickets. In this disease – also called "bone softening" – bones need the essential calcium, as the consequence is their impaired mineralization, which leads to shortened and crooked limbs. However, vitamin D deficiency can also intensify diseases of old age like osteoporosis.

A healthy Central European adult who walks daily for approx. 20 to 30 minutes in the sun can fully satisfy their vitamin D need.

What is Vitamin D and how is it synthesized?

Vitamin D is one of the few vitamins that human beings can synthesize themselves. Thus, its name "vitamin" is not fully applicable because it is actually a prohormone. Still the name "vitamin D" was kept due to historical reasons. Vitamin D is activated through sunlight – to be more precise, UV-B radiation – on the skin. Vitamin D3 is synthesized from dehydrocholesterol. From the blood, it reaches the liver, where it is converted to its storage form.

A healthy Central European adult who walks daily for approx. 20 to 30 minutes in the sun can fully satisfy their vitamin D need. After about 30 minutes, approx. 250 micrograms of vitamin D have been synthesized on a pretty summer day. The body then virtually stops the synthesis to rule out an overdose caused by excessive sunlight. Unneeded vitamin D can be stored in fatty tissue, to be retrieved and activated in the winter months when the sun cannot send us enough UV-B radiation to synthesize new vitamin D. Therefore, it is important to refuel enough sunshine in the summer so we have a sufficient supply of vitamin D.

Vitamin D synthesis supported by the sun – is it that simple?

In order that the body itself can synthesize vitamin D, enough naked skin needs to be exposed to the sun to start synthesizing it. Too many clothes and sunscreen with high sun protection factor can interfere with vitamin D synthesis because they prevent UV-B radiation from reaching the skin. Then, should we apply less sunscreen? This is a real dilemma in times when there are more justified warnings about the danger of skin cancer. 

However, in the winter months it can easily happen that not enough 'sun is refueled’ to satisfy the need for vitamin D3. In Central Europe, the angle of incidence of sun rays is too flat, so the needed UV-B radiation cannot even reach us. North of the 42nd parallel (i.e. the approximate location of Barcelona or Boston), this is the November to February time period; north of the 52nd parallel (i.e. north of Berlin or Edmonton), this is even from October to March. Persons with darker skin have more difficulties to synthesize enough vitamin D3 than lighter-skinned ones – the darker the skin color, the slower vitamin D synthesis takes place. To compensate for this, darker skin is better protected from the damaging effects of sunlight, thus allowing sunbathing a little longer without risking sunburn. The solution for this dilemma lies, as always, in the middle: Sun on naked skin is alright – but if you intend to spend several hours outdoors right away, then never forget to apply sunscreen! Do not expose yourself to the sun too long and only according to your skin type.

Vitamin D in foods

Luckily, vitamin D3 can be absorbed from foods – albeit to a limited extent – for example with

  • cod liver oil,
  • fatty fish,
  • seafood,
  • eggs, and
  • dairy products.

The elderly need more vitamin D due to the higher risk for osteoporosis. They are often less mobile, something that can shorten outdoor stays. In addition, production in the skin falls considerably with advanced age. Nutritionally speaking, the elderly also have a harder time to satisfy their need for vitamin D or even to compensate for a multiple need. To counteract vitamin D deficiency, it can be an especially good idea to take vitamin D supplements.

What is the role of magnesium in our bones?

Magnesium is known above all for its function in our muscles. All our muscles need magnesium so they can relax again after physical stress. Therefore, magnesium deficiency quickly manifests itself in nightly calf cramps and arrhythmia – because the heart is as well "only" a muscle. In women's health, it also plays an important role owing to its antispasmodic effect. Magnesium can be stored in our body; however, not in our fat reservoirs as is the case with vitamin D, but in our bones and teeth. About 60 percent of the 25 g of magnesium that we carry in our body is therefore bound in the bones and teeth. Only about 1 percent of the entire magnesium is transported protein-bound in our blood. The remaining magnesium is distributed in the muscles and soft tissue, where it is bound, for example, to ATP (adenosine triphosphate, the fuel of our cells) to perform its tasks. In the bones the stored magnesium is not passive, but contributes to bone stabilization and to bone growth and mineralization. If there is a lack of it, important functions can no longer be carried out and diseases like osteoporosis can worsen. Both minerals are therefore important for bone cells. Thus, calcium and magnesium should logically be provided to the body in sufficient quantities both with the daily diet and with beverages like mineral water. If a deficiency has already been detected; it should be treated with suitable medications. Last but not least, magnesium also plays an important role in vitamin D activation. Vitamin D – or to be more precise – calcitriol in turn regulates calcium and magnesium resorption in the small intestine. Because of that, both biofactors directly and crucially influence their absorption from foods.

Calcium and magnesium should be provided to the body in sufficient quantities both with the daily diet and with beverages like mineral water.

How much magnesium do our bones need?

Since there is relatively little magnesium in the average Western European diet, a slight magnesium deficiency is quite common. Many other factors of our everyday life make us use up more magnesium or excrete it more than usual.

When exercising, for example, increased muscle function consumes magnesium, which is also excreted with the sweat. Persons with chronic diseases such as diabetes also excrete more magnesium. Depending on age and gender, healthy individuals should take between 300 mg and 400 mg of magnesium, as recommended by the German Nutrition Society. Those who belong to a risk group or have a higher need owing to medications should consult with their physician before taking more magnesium to prevent a deficiency.

Magnesium is found in these foods

Magnesium is found in cereals, nuts, seeds, soy and cocoa, among others. Examples are

  • quinoa,
  • amaranth,
  • pumpkin and sunflower seeds,
  • sesame seeds,
  • almonds,
  • dark chocolate,
  • tofu
  • seaweed and
  • certain mineral waters.

Thus, when buying mineral water, in addition to the calcium content, pay attention to the magnesium content per liter so you can easily satisfy your magnesium needs.

Osteoporosis prevention consists of more than just calcium

When thinking about the subject of osteoporosis, don't just think of your bones and the necessary calcium – the complex processes in our body need more than that for functioning well. Only together with a well-adjusted magnesium and vitamin D balance it is possible to effectively prevent osteoporosis and allow the calcium to reach the places where it is needed the most. Never forget to discuss preventive measures with a physician, because even these measures should be customized on a case-by-case basis.

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