Calcium, the most abundant mineral in the human body, has several important functions. More than 99% of total body calcium is stored in the bones and teeth where it functions to support their structure . The remaining 1% is found throughout the body in blood, muscle, and cells of soft tissue. Calcium is needed for muscle contraction, blood vessel contraction and expansion, the secretion of hormones and enzymes, and sending messages through the
nervous system .
When calcium intake is low or calcium is poorly absorbed, bone breakdown occurs because the body must use the calcium stored in bones to maintain normal biological functions such as nerve and muscle function. Bone loss also occurs as a part of the aging process. A prime example is the loss of bone mass observed in post-menopausal women because of decreased amounts of the hormone estrogen.
When can a calcium deficiency occur?
Inadequate calcium intake, decreased calcium absorption, and increased calcium loss in urine can decrease total calcium in the body, with the potential of producing osteoporosis and the other consequences of chronically low calcium intake. If an individual does not consume enough dietary calcium or experiences rapid losses of calcium from the body, calcium is withdrawn from their bones in order to maintain calcium levels in the blood.
Who may need extra calcium to prevent a deficiency?
Menopause often leads to increases in bone loss with the most rapid rates of bone loss occurring during the first five years after menopause. Drops in estrogen production after menopause result in increased bone resorption, and decreased calcium absorption . Annual decreases in bone mass of 3-5% per year are often seen during the years immediately following menopause, with decreases less than 1% per year seen after age 65.
Although osteoporosis affects people of different races, genders and ethnicities, women are at highest risk because their skeletons are smaller to start with and because of the accelerated bone loss that accompanies menopause. Adequate calcium and vitamin D intakes, as well as weight bearing exercise are critical to the development and maintenance of healthy bone throughout the lifecycle.
What is the recommended intake for calcium?
MALE AND FEMALE AGE CALCIUM(mg/day) Pregnancy and Lactation
6 to 12 months 270 N/A
1 to 3years 500 N/A
4 to 12 years 800 N/A
13 to 18 years 1300 1300
19 to 50 years 1000 1000
51 + years 1200 N/A