Food Standards Agency, Aviation House. 125 Kingsway,
London, UK WC2B 6NH. Telephone: 020 7276 8000.
Website:<http://www.eatwell.gov.uk>
International Food Information Council. 1100 Connecticut
Avenue, NW Suite 430, Washington, DC 20036. Tele-
phone: 202-296-6540. Fax: 202-296-6547. Website:
<http://ific.org>.
OTHER
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Tish Davidson, A.M.Calcium
Definition
Calcium (Ca) is the most abundant mineral in the
body. About 99% of calcium in the body is in bones
and teeth. The remaining 1% is in blood and soft
tissue. Calcium in body fluids is an electrolyte with a
charge of +2. Humans must meet their need for cal-
cium through diet.Purpose
Calcium is essential for:
building and maintaining strong bones and teeth
muscle contraction
blood vessel contraction and relaxation
nerve impulse transmission
regulating fluid balance in the bodyDescriptionMost calcium in the body is stored in bones and
teeth. Here it combines with phosphate to form strong,
stable crystals. The remaining 1% is dissolved in body
fluids and much of it forms Ca 2+ ions. In the body,
these electrically charged particles are calledelectro-
lytes. Calcium and other electrolytes are not distributed
evenly throughout the body. Dissolved calcium is
found mainly in the fluid outside cells (extracellular
fluid). Metabolic events cause the movement of calcium
across cell membranes result in muscle contraction,
nerve impulse transmission, and various chemical reac-
tions. The cell then uses energy to restore the balance of
calcium between the inside and outside of the cell mem-
brane, so that the event can be repeated.
To remain healthy, the amount of calcium dissolved
in body fluids must be stay within a very narrow range.
Bone acts like a calcium bank.Bone is constantly being
broken down by cells called osteoclasts and built upCalciumRecommended dietary Tolerable upper
Age allowance (mg) intake level (mg)
Children 0–6 mos. 210 (AI) Not established
Children 7–12 mos. 270 (AI) Not established
Children 1–3 yrs. 500 2,500
Children 4–8 yrs. 800 2,500
Children 9–13 yrs. 900 2,500
Adolescents 14–18 yrs. 1,300 2,500
Adults 19-50 yrs. 1,000 2,500
Adults 50 yrs. 1,200 2,500
Pregnant women 18 yrs. 1,300 2,500
Pregnant women 19 yrs. 1,000 2,500
Breastfeeding women
18 yrs. 1,300 2,500
Breastfeeding women
19 yrs. 1,000 2,500
Food Calcium (mg)
Yogurt, plain, 1 cup 415
Cheese, mozzarella, 1.5 oz. 372
Sardines with bones, canned in oil, 3 oz. 324
Cheese, cheddar, 1.5 oz. 305
Milk, any type, 1 cup 300
Yogurt with fruit, 1 cup 245–384
Tofu, firm, with calcium sulfate, ½ cup 204
Orange juice, fortified, 6 oz. 200–260
Salmon with bones, canned, 3 oz. 181
Spinach, cooked, ½ cup 120
Beans, white, cooked, ½ cup 113
Instant breakfast drink, powder, prepared with water 105–250
Cereal, fortified, 1 cup 100–1,000
Bok choy, cooked, ½ cup 61
Beans, pinto or red, cooked, ½ cup 43
Bread, whole wheat, 1 slice 20
AIAdequate intake
mgmilligram(Illustration by GGS Information Services/Thomson Gale.)Calcium