Calcium is a mineral that can be found in the highest proportion in our bodies. It makes 1.5-2% of our bodyweight, 99% of which can be found in the bones.
- Stronger bones and joints
- Calcium helps your body build strong bones and joints. Calcium and regular exercise are especially important in the prevention of osteoporosis.
- Helps prevent muscle cramps
- Calcium and magnesium together can help prevent or diminish muscle cramps.
- Lowering blood pressure
- Sufficient intake can lower high blood pressure, so it indirectly helps preserve the health of the blood vessels as well.
- Preventing obesity
- Calcium may prevent obesity and help improve body composition (at present, however, there is no evidence for this).
In nature, calcium appears in compounds like sulfate salts or carbonates. An average human body contains about 1000 grams of calcium (1000-1200 g for men and 750-850 g for women), 99% of which is built in the teeth and the bones, while the rest is in the blood plasma, the cells and the extracellular fluid. Calcium plays a role in blood clotting and diminishes allergy symptoms. It is also inevitable for the functioning of the neurons and for proper muscle contractions, although it doesn’t improve performance directly. In case of deficiency, calcium will be extracted from the bones, which will make them weaker. Acidification of the body and high protein intake can increase the amount of calcium in the urine, and insufficient intake might even cause cardiac arrhythmia. Signs of calcium deficiency include muscle cramps or muscle twitching in both young and old people. In children, long-term insufficient intake can result in rachitis (vitamin D deficiency), while in adults, it can result in osteoporosis. Calcium metabolism is regulated by calcium and vitamin D intake and hormones produced by the parathyroid glands: parathormone and calcitonin. Calcitonin reduces calcium level in the blood and helps calcium build into the bones, while parathormone increases calcium level in the blood through extracting calcium from the bones and reducing excretion. Corticosteroids have a negative impact on bone strength, while estrogens and androgens (especially androgens) make the bones stronger through increasing their calcium content.
When it comes to calcium, there are two questions we cannot evade. Both of them are particularly important for athletes. The first is about the supposed harmful effects of high protein intake; the second is about the possible negative impacts of low bodyfat and extreme dieting can have on the calcium balance o the body.
Many studies have shown that high protein intake (especially from animal sources like meat) increases calcium excretion, while other studies have not shown such correlation. If you live a physically active lifestyle (including exercises that exert load on the bones like weight training), high protein intake is not likely to make your bones weaker, especially if your calcium intake is sufficient (and you should not forget about fruits and vegetables either).
In women, low bodyfat and related hormonal imbalance significantly increase the risk of osteoporosis (although this is less likely to affect women who do weight training), so it is definitely important to provide sufficient mineral intake. Fun fact: some believe that calcium reduces fat storage, so it may help you in shredding (as for myself, I cannot confirm that, even though I have drunk several thousand liters of milk in my life). Fast weight loss may rev up bone loss, so at times like this, you should devote extra attention to getting enough exercise, calcium and vitamin D.
Benefits of calcium: strong bones and teeth; preventing osteoporosis and broken bones; lowering blood pressure; reducing PMS symptoms; preventing muscle cramps; and maybe reducing bodyfat. If you take calcium supplements, it is recommended to take several smaller doses during the day, with plenty of fluid. In adults, 20-40% of the ingested calcium gets absorbed. It is not recommended to take more than 2000 mg a day (like 5000 mg/day) on a regular basis. If you are prone to kidney stones, supplementation in large amounts is not recommended either. May cause constipation.
Calcium can be found in dairies and nuts in larger amounts, but the absorption ratio is lower in the case of nuts. Mineral waters high on calcium can contribute to calcium intake, too. In supplements it is usually found in the form of calcium-lacticum, -gluconicum, -carbonicum or -hydrogenphosphoricum. Some supplements might contain natural sources of these compounds as well, like chalk or egg shell. Further compounds: calcium aspartate, calcium citrate; calcium citrate malate, calcium orotate.
Why it is worth using
- It can be useful in the treatment of irritability, poor mental focus or sleeping disorder.
- Both calcium and magnesium can be successfully used in preventing muscle cramps.
- In case of allergic reactions, oral or intravenous calcium intake can help, even though it cannot substitute a medical intervention.
- It is a common compound of antacids. In this form it can ease heartburn.
How to use it
The ideal proportion of magnesium and calcium is 1:2. This means, if you take 1000 mg calcium with supplements, it is recommended to take 500 mg of magnesium, too. The proportion of calcium and phosphor is appropriate between 1:1 and 1:1.5. It is not worth taking more than 500 mg of calcium at a time. Fast weight loss may rev up bone loss, so at times like this, you should devote extra attention to getting enough exercise, calcium and vitamin D.
|Young people between 15 and 18 years||1000-1200 mg/day
(according to other–more recognized–sources):
|Pregnant or breastfeeding women:||1200 mg/day|
|Osteoporosis treatment and prevention:||1200 mg/day|
|Strength and dynamic strength sports:||1500-2000 mg
(according to other sources): 1800-2500 mg/day
|Endurance sports:||1000-2000 mg
(according to other sources): 1500-2000 mg/day
Interactions and synergies
- Lactose, vitamin C and vitamin D influence calcium absorption positively.
- Sufficient protein intake supports the building of bones.
- However, high protein and phosphate intake increases calcium excretion.
- Phytic acids in grains, foods containing oxalic acid (e.g. spinach, or rhubarb) and vegetable and fish oils (PUFA) block absorption.
- It may get into interaction with antibiotics, so you should ask your physician whether you can take calcium together with antibiotics.
- If you take diuretics, you should follow your doctor’s advice regarding the use of supplements that contain calcium, because diuretics may cause too low or too high blood calcium levels.
- Also consult your physician if you are on medication for cardiac diseases.
- Ipriflavone enables more calcium to build into the bones, so it is used in the treatment of osteoporosis.
- Coffee, tea and caffeine increase calcium excretion: each cup of coffee increases the calcium requirement of the body by 100 mg.
Calcium can be found in dairies and nuts in larger amounts, but the absorption ratio is lower in the case of nuts. Mineral waters high on calcium can contribute to calcium intake, too.
Calcium content of raw ingredients in mg (per 100 grams)
|Whole wheat||39 mg|
|Cow’s cottage cheese, low-fat||90 mg|
|Cow's milk, skim||114 mg|
|Cow's milk, whole||120 mg|
|Soy flour||200 mg|
|Sheep milk cheese||400 mg|
|Trappist cheese||600 mg|
|Cheese (depending on sort)||400-800 mg|
|Parmesan cheese||850 mg|
|Poppy seeds||968 mg|
|Powdered milk||1200 mg|
Possible side effects
Avoid excessive intake if you have any health issues, especially serious kidney disease. It is not recommended to take more than 2000 mg a day (like 5000 mg/day) on a regular basis. If you are prone to kidney stones, supplementation in large amounts is not recommended either. May cause constipation.
Calcium compounds have been known and widely used for millennia. Metallic calcium was first isolated by Sir Humphry Davy in 1808.
Can I prevent osteoporosis by taking calcium and vitamin D simultaneously?
These two substances do not prevent osteoporosis by themselves, but they can support prevention and treatment. Osteoporosis is a multifactorial disease. The use of mineral and vitamin supplements together with proper physical activity and protein intake contribute to slowing down the progress of bone loss, therefore it may be beneficial. You should follow your physician’s advice if you have an existing condition or you are exposed to increased risk.
In which cases is it worth considering taking a calcium supplement?
If you cannot provide your daily intake by nutrition. This can be the case if you are on a diet, allergic to milk proteins etc. Many bodybuilders exclude dairies from their diets completely. In this case, it can be a good idea to take effervescent calcium tablets or other forms of supplements.
Dr. Sajtos János, A kalcium-anyagcsere, Új Diéta, 2001
Cappuccio FP, Elliott P, Allender PS, et al. Epidemiologic association between dietary calcium intake and blood pressure: a meta-analysis of published data. Am J Epidemiol. 1995;142:935–945.
Rodrâiguez JA, Novik V. Calcium intake and bone density in menopause. Data of a sample of Chilean women followed-up for 5 years with calcium supplementation. Rev Med Chil. 1998;126:145–150.
Shils ME, Olson JA, Shike M, Ross AC. Modern Nutrition in Health and Disease. 9th ed. Baltimore, Md: Williams & Wilkins; 1999:169–192, A127–A128.
Sonnenblick M, Abraham AS, Meshulam Z, Eylath U. Correlation between manifestations of digoxin toxicity and serum digoxin, calcium, potassium, and magnesium concentrations and arterial pH. BMJ. 1983;286(6371):1089-1091.
Stier CT Jr, Itskovitz HD. Renal calcium metabolism and diuretics. Ann Rev Pharmacol and Toxicol. 1986;26:101-116.
Thys-Jacobs S, Starkey P, Bernstein D, Tian J. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. Premenstrual Syndrome Study Group. Am J Obstet Gynecol. 1998;179:444–452.
Ask your question about this article here!
You can ask questions after registration and login!
Please log in!