IAs and
ULs for calcium are measured in milligrams (mg).
The following list gives the recommended AL and
UL levels of calcium for each age group.
- children birth–6 months: AI 210 mg; UL not established;.
- children 7–12 months: AI 270 mg; UL not established.
- children 1–3 years: AI 500 mg; UL 2,500 mg
- children 4–8 years: AI 800 mg; UL 2,500 mg
- children 9–13 years: RDA 9 mg; UL 2,500 mg
- adolescents 14–18 years: IA 1,300 mg; UL 2,500 mg
- adults age 19–50: RDA 1,000 mg; UL 2,500 mg
- adults over age 50: RDA 1,200 mg; UL 2,500 mg
- pregnant women 18 years and younger: RDA 1,300 mg; UL 2,500 mg
- pregnant women over age 18: RDA 1,000 mg; UL 2,500 mg
- breastfeeding women 18 years and younger: RDA 1,300 mg; UL 2,500 mg
- breastfeeding women over age 18: RDA 1,000 mg; 2,500 mg
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 calcium
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 body
Most 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 called electrolytes.
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 reactions.
The cell then uses energy to restore the balance of
calciumbetween the inside and outside of the cell membrane,
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 up again by cells called osteoblasts. This process is called
bone remodeling, and it continues throughout an individual’s
life.
