If any mineral deserves recognition for strong bones and teeth, it has to be calcium.
The where, what and how of calcium:
Dairy products are a source of calcium. Calcium is the mineral that helps build bones and teeth. Calcium also helps muscles and nerves to work properly, helps blood to clot and regulate enzyme activity.
Calcium is your bone-building partner throughout life!
Bone-building years
From birth, bones continue to be built and grow. Consuming enough calcium during the bone-building years (8 - 18 years of age) is crucial to help maximise bone density and reduce the risk of osteoporosis later on in life. Bone mass can be improved through the combination of increased intake of calcium and physical activity.
Calcium recommendations throughout the life cycle and for certain physical conditions:
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Important life stages
|
Calcium recommendations (mg/day)
|
Suggested servings per day
|
|
Newborn up to 6 months
|
300 (breast milk) 400 (cow's milk)
|
|
|
Baby & toddler
|
6 – 12 months 270
1 – 3 years 500
|
2
|
|
Children
4 – 9 years
|
800
|
2 - 3
|
|
Adolescents
10 – 19 years
|
1300
|
4
|
|
Adults
> 20 years
|
1300
|
4
|
|
Elderly
65 years
|
1300
|
4
|
|
Physical Conditions
|
|
Pregnancy*
|
1200
|
4
|
|
Lactation
|
1300
|
4
|
|
Menopause
|
1300
|
4
|
*Calcium absorption during pregnancy is enhanced due to increased hormonal levels during this period
Loss of bone mass
Osteoporosis is a condition in which bone loses calcium and other minerals, which can increase the risk of fracture. It is often referred to as the ‘silent disease’, as bone loss happens without you even being aware of it. Bone loss is gender-dictated: in men it is a slow, uniform process (0.5% per year); while in women the loss of bone accelerates after menopause.
The following table shows the stages of bone mass development throughout life:
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Phases
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Age
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Development
|
|
Rapid bone growth phase
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From birth to 20 years
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Maximum development of bone mass with adolescence being the key period. From 8-18 years, 50% of bone mass is acquired.
|
|
Plateau phase
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20 - 30 years
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With enough calcium-rich food and physical exercise, optimal bone mass is obtained.
|
|
Bone loss phase
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30 years until life ends
|
Loss of bone is unavoidable. It starts at around 30 years.
|
Did you know?
One glass of milk (250 ml) provides 300 mg of calcium, which equals one serving of dairy. Dairy products are a source of bioavailable calcium. This means that your body can use most of the calcium found in dairy effectively.
The amount of different foods or products necessary to obtain 300 mg calcium, are indicated in the table below.
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Calcium source (≈ 300mg)
|
1 serving
|
Calcium source (≈ 300mg)
|
1 serving
|
Calcium source (< 300mg)
|
|
Milk
|
250 ml
|
Spinach, cooked
|
2 cups
|
Bread
|
|
Yoghurt
|
200 ml
|
Broccoli, cooked
|
7 cups
|
Fruits
|
|
Cheese
|
40 g
|
Cabbage, cooked
|
9 cups
|
Maize meal
|
|
Sardines
|
130 g
|
Beans, cooked
|
3 cups
|
Pasta
|
Bone mass built during childhood and adolescence determines bone health later on in life.
Three servings of dairy every day from early childhood are recommended. Remember, you need 3-A-DAY™!
Read more about how calcium helps bone health and prevent osteoporosis!
References
Bhatia v. 2008. Indian J Med Res. 127:269-273
Gibney MJ, et al. 2002. Introduction to Human Nutrition. UK. Blackwell Publishing
Heany RP, et al. 1988. Calcium absorbability from spinach. Am J Clin Nutr. 47:707-709
Kalkwarf HJ, et al. 1997. N Eng J Med. 337:523-528
Kinaymu HK, et al. 1997. J Bone Mineral Res. 12(6):922
Smit LE, et al. 1998. The Nutritional content of South African milk and liquid milk products. Dairy Industry Centre, Agricultural –Animal Nutrition and Animal Products Institute, Irene
Smit LE& Schönfeldt HC. 2006. The Nutritional content of South African milk and milk products. Dairy Industry Centre, Agricultural –Animal Nutrition and Animal Products Institute, Irene
US Department of Agriculture (USDA) - Agricultural Research Service. 1998. USDA Nutrient database for Standard Reference release 12. http://www.ars.usda.gov/nutrientdata
Wardlaw GM & SMITH AM. 2006. Contemporary nutrition, 5th Edition. McGraw and Hill. USA.
Whitney EN & Rolfes RR. 2002. Understanding nutrition, 9th Ed. London. Wadsworth
Weaver CM & Plawecki KL. 1994. Am J Clin Nutr. 59(Supplement):1238S-1241S
Weaver CM, et al. 1999. Am J Clin Nutr. 70:543S-548S