Calcium – The Most Important Mineral

By Dave Moore

From the point of view of an athlete, and especially a bodybuilder, if we asked them what were the most important minerals they would probably say, “Iron, zinc and calcium”. And it is possible a nutritionist would agree with this, but if we asked the body it would definitely say, “Calcium, calcium, calcium”, because of the much greater amounts of calcium that are needed and the priority it has in the human body.
You may not be aware of the role calcium plays in many essential functions, some of which are quite interesting, as there are studies that now show that, as well as contributing to proper muscle function, calcium can also aid fat loss.

The five macro-elements that make up approximately 96% of body weight – oxygen, hydrogen, nitrogen, carbon and sulphur – are largely obtained through breathing and eating. For example, oxygen is in the air we breathe, water supplies great quantities of hydrogen, nitrogen is in the proteins we eat, sulphur is contained in amino acids methionine and cysteine, as well as vitamins thiamine and biotin, and carbohydrates are made up of carbon (carbo-) and hydrogen (-hydrate), and oxygen in the correct proportions to make water.
You would think that through the three macronutrients – proteins, fats and carbohydrates – in our diets all requirements for essential elements would be covered, but it’s not that simple. There is also what is known as micronutrients, so called because they are required in very small amounts, which are just as essential to human life. These are mainly vitamins and minerals and there are macro- and micro- components to them as well, as some are needed in measures of milligrams (mg) and others only in micrograms (ug).
Although all of these are important, perhaps the one of greatest significance is calcium. 

The Macro-minerals: Calcium, Phosphorus & Magnesium
Calcium, phosphorus and magnesium are known as the macro-minerals because they are the ones found in highest concentration in the human body. Average daily intake would be around a few hundred milligrams, while reserves in the body could vary from dozens to hundreds of grams.

Calcium
An adult of 70kg might contain 1-1.5kg of this mineral.
Calcium is essential to the formation of bones, and thus 99% of calcium in the body is found in bones and teeth, and the other 1% is mainly found in body fluid surrounding the cells with a smaller amount in the cells’ interior.
Most people think that once bones are formed they do not change, or are inert, but they are very much alive and in continual evolution, degradation and regeneration. Calcium is present in bones in the form of calcium phosphate, which is why ingesting calcium and phosphorus is important to bone health. In fluids it is found in an ionic form, like calcium carbonate.
As well as being important for the skeletal system, calcium takes part in many other functions in the body, such as the regulation of ion through cellular membranes, which facilitates cellular permeability; as such it also assists the transmission of nervous impulses, muscle contraction, and heart beat; it helps maintain blood pressure; plays an important role in blood coagulation; and helps keep cells together.
Due to its multiple functions there is a continual demand for calcium in the body, and if sufficient is not available the body resorts to its natural deposit. That is the skeleton, which acts as a mineral bank, and the body takes what it needs. Naturally, if you are always making withdrawals from the bank and not enough deposits, in the long term there will be a deficit, and for the skeleton that means the weakening of bones known as osteoporosis.
Normally, the body takes the calcium it is lacking from the bones if it is not available from the diet, and replaces it when more becomes available, which is why the bones are constantly active, and bone regeneration takes place through one’s entire life. As such, athletes need to ensure they get optimum amounts of calcium and its co-factors vitamin D, boron, copper, manganese and zinc, as calcium cannot build a molecule of bone unless these other elements are present. 

Calcium Deficiency
A deficiency of calcium in the first years of and during bone formation results in stunted growth and rickets. In adults it is less common, as the body extracts any lacking calcium from the skeletal system and osteoporosis only appears after many years as the bones become weaker.
The most obvious symptoms of a lack of calcium in adults are fatigue and muscles cramping. 

Toxicity
Ingesting excessive calcium is not especially toxic and has no serious side effects, apart from constipation and an increased risk of developing kidney stones. High calcium consumption can also impede the absorption of other minerals like iron, zinc and magnesium. However, prolonged high levels of calcium can lead to certain problems with kidney function. 

Recommended Dose
The RDI for calcium is established at 1000mg, but athletes could perfectly well ingest double or even more without any problems arising. These recommended doses were calculated in the 1960’s based on a 2000 calorie/day diet, so the figures may be somewhat obsolete, apart from the fact that an athlete, especially a bodybuilder in the development phase, consumes many more calories than that. 

Calcium Sources
The main sources of calcium in the diet are milk and dairy products, ice cream, cream, cheese, broccoli, sprouts and seeds, green vegetables, oysters, prawns, salmon, clams, beans and peanuts.

Sporting Benefits
It is well known that calcium keeps bones healthy, but few people know it plays a big role in sports performance. When there is a lack of calcium the muscles cannot relax, which reduces energy potential and causes less satisfactory contractions. Shallow contraction means deficient training and not much growth. With better muscle relaxation one avoids cramps and injuries.
On the other hand, no athlete can perform properly without a solid, healthy skeletal system. Recent evidence suggests that calcium supplements have a positive effect on aerobic and anaerobic performance. Doctor T. Nishiyama claimed an increase in strength and Dr. J. H. Richardson showed that calcium supplements delayed the appearance of fatigue during physical exercise of longer durations.

Calcium & Fat Loss
Most recently calcium has been shown to play a positive role in fat loss. For example, one study showed that with an increase in calcium in the diet together with a normal protein intake, the expulsion of fat in faeces increased, to the equivalent of 350 calories/day.
Various studies have also shown that calcium was key to regulating body weight and especially to the metabolizing of fat, through the activation of lipolysis, the oxidisation of fat and total energy expenditure. For example, Zemel et al (2002) observed the effects of calcium supplement on obese adults who were dieting and found that the moderately high ingestion of calcium – 1200-1300mg/day – promoted more fat loss than in those who only consumed 400-500mg/day. Another study carried out in 2004 showed that calcium supplements for people dieting to lose weight prevented the “rebound” effect, and they did not put the weight back on as soon as they stopped the diet, which was a common problem for others with lower calcium consumption. 

Conclusion
As you can see, optimum levels of calcium can do a lot for your general health, maintaining a sound skeletal system, sports performance and for staying trim.