Calcium

Definition

Calcium is the most bountiful mineral in human body, that is to say 1,200 g in adults. It is with phosphorus the main component of bones.

Roles in the body

99 % of calcium allow the development and solidity of bones and teeth. Non bonny calcium is however essential because it steps in numerous vital functions: blood coagulation, muscular contraction, nervous conduction, and also hormones’ release. The interest for calcium is more and more proved in the reduction of the high blood pressure risk and colon and prostate cancers.

In the bones, calcium is bound to phosphorus; the whole is solidified thanks to fluorine molecules.

Sources in vegetables and some others food products(*Ciqual Data)

Milk and dairy products like cheeses are our first dietary sources of calcium (more than two thirds of calcium that we consume). The last third of our needs is covered thanks to our consumption of some leafy vegetables, dried fruits and mineral waters.

 

Food products’ contents in calcium*	mg / 100g
Cantal - Comté	970 - 880
Chervil – Almond - Parsley	260 - 250 - 200
Dandelion - Watercress	165 - 157
Eggyolk	137
Pistachio	135
Semi – skimmed milk	114
Black radish - Spinach	105
Broccoli – Oyster – Swiss chard – Red beans – Black olive – White beans – Black currant	93 - 92 - 80 - 66 - 61 - 60 - 60

Recommended intakes

Calcium is vital, everybody knows that, to the individual growth since the first months of maternity. But what we know less is that bony structure is developing after the height growth of the person. The thickness growth of bony tissue lasts until 19, 20 or even 25 years old.

Whatever the age, it is fundamental to assure the daily and sufficient intakes of calcium. Having dietary intakes near the values of recommended intakes is a mean to cover the real needs of each person. It is particularly important to have good intakes of calcium at the moment when the bony structure, commanded by genetic heritage, is developing that is to say during the childhood and the adolescence but also at the time when appear the unavoidable physiological ageing, in order to reduce osteoporosis risks. Among French population, the percentages of people who don’t have the two thirds of the recommended intakes in calcium are quite important: about 20 % of men aged from 18 to 65 years old, 30 % of adolescents and women aged from 18 to 50 years old, about 50 % of men of more than 65 years old and 75 % of women of ore than 55 years old.

In order to a correct assimilation of calcium and fixing it in bones, it is necessary to eat as calcium as phosphorus, a good quantity of vitamin D and a bit of fluorine.

* Afssa data

The average recommended daily intake is of 0.8 g of calcium for an adult.

The advised nutritional intakes are given for the French population according to the age but also depending on physical activity and individual status (pregnancy, lactation…).

Ages	Advised Nutritional  intakes (mg a day)
Children1-3 years	500
Children 4-6 years	700
Children 7-9 years	900
Children 10-12 years	1 200
13-15 years(boys)	1 200
13-15 years (girls)	1 200
16-19 years (boys)	1 200
16-19 years (girls)	1 200
Adults (men)	900
Adults (women)	900
> 75 years	1 200
Pregnant women	1 000
Breast-feeding women	1 000

* ANC 2001

Deficiencies and excess

The calcium blood rate is maintained between narrow limit values, at the expense of bony stocks. The consequences of a diet that doesn’t bring enough calcium are obvious only when bony modifications are occurring: bad bony structure in young people, decalcification in adults and old people.

 The deficiency signs on the long range are: osteoporosis in adults and rickets in children, skeletal and articulation distortions, bony pains, muscular and abdominal cramps, tetanies, pins and needles in the extremities of fingers, nervousness and fretfulness, memory disorders, headaches or also respiratory problems.

In a healthy subject, calcium dietary excess is deleted by stools, urine, sweat and milk for breast-feeding women. In a more sensitive subject, a high calcium intake (until 2 g a day) can lead to stones in the bladder.

 

Weak points

In spite of a good dietary intake of calcium, it could happen a bad fixation of it in bones because of disorders during the calcium absorption or during the kidney elimination.

Cleverness and advices of the nutritionist

Even if the calcium intakes play an important role in the reduction of osteoporosis risk, it is vital to also appeal to others efficient prevention means such as:  the vitamin D intake for the intestinal absorption of calcium and hormonal treatment substitutive to menopause and physical activity.