The body contains about 2 percent of calcium with 98 percent of it in the bones. A primary structural constituent of the skeleton, its major role is that of keeping the bones and teeth strong.  

Though nearly all of the calcium (99 percent) in the body is stored in the bones, the body can draw upon these calcium reserves and use it elsewhere, like in the bloodstream and soft tissues. The remaining 1 percent is stored throughout the body in blood, muscle, and the fluid between cells. The three major regulators of blood calcium are parathyroid hormone (PTH), vitamin D, and calcitonin.


Because of its close association with bone and teeth health, attention should be paid to adequate calcium intake from early childhood and well into adulthood. Humans begin accumulating calcium in the bones as babies. This accumulation of calcium in bones continues until it peaks in early adulthood. Bone loss and calcium decline begin at the mid-30s with the process of bone remodeling.

Bone remodeling is an ongoing process in which breakdown of bone material is replaced by calcium deposited in the blood. When the levels of calcium in the bloodstream fall too low, there is a breakdown of calcium reserves in the bone to replenish the calcium in the bloodstream.  After 30 bone resorption happens at a faster rate than bone synthesis. This is a very gradual decline, as low as percent every year, and lead to calcium depletion in bones.

Bone Remodelling  

Since calcium is not produced by the body, early attention to strong bones in childhood and adulthood will provide more stable bone mass during the aging years. To avoid deficiency of calcium consume adequate measures of calcium from an early age. Eating a well-balanced diet, rich in necessary nutrients, and exposure to vitamin D from diet, or exposure to the ultraviolet light of the sun, increases calcium absorption. Calcium absorption ability of the body declines with age.


The dietary requirements of calcium and other collaborative nutrients vary slightly around the world. The requirement of calcium in the body is greatest during periods of growth such as childhood, amongst pregnant women, and women who are breastfeeding.

The RDA for calcium for children and teenagers in the age group 9-18 is 1300 mg per day. For adults in the age bracket 19-50 it is 1000 mg per day. Women above the age of 50 and men above the age of 70 should increase their daily intake of calcium to 1200 mg per day.

Calcium: Functions, Deficiency, and Food Sources

Calcium is the most abundant mineral in the human body and has several important functions like:

  1. An adequate level of calcium reduces the risk of osteoporosis and bone fractures.
  2. Cells use calcium to send and receive neurotransmitters during communication with other cells.
  3. It is one of the key elements in maintaining a regular heartbeat.
  4. Eating calcium-rich foods may decrease your risk for overweight and obesity.
  5. It is essential for blood clotting.
  6. Calcium stabilizes blood pressure.
  7. It contributes to normal brain functioning.
  8. It facilitates the process of contraction of muscle cells and blood vessels.
  9. Aids the process of fertilization by assisting the movement of sperms to the eggs.
  10. Helps maintain insulin levels in the body by opening cells to glucose.
  11. Stimulates enzyme and hormone secretion.
  12. Regulates fluid balance by controlling the flow of water into and out of the cells.


Calcium deficiency is a condition in which the body has an inadequate amount of calcium. Two types of calcium deficiency are:

  1. Dietary calcium deficiency: Caused by an inadequate calcium intake, it causes thinning and weakening of the bones and osteoporosis. Lactose intolerance due to lactase deficiency is a common cause of low calcium intake.
  2. Hypocalcemia: It is the low level of calcium in the blood which can occur due to certain medicines or medical conditions.


Untreated calcium deficiency can lead to serious complications and long-term effects on the health like:

  1. Skeletal abnormalities like osteopenia, osteomalacia, osteoporosis, and rickets.
  2. Hypertension and high blood pressure.
  3. Calcium deficiency causes dry skin and brittle nails.
  4. It can cause yellowing of teeth.
  5. Nervous system afflictions like muscle cramps, numbness and tingling in the arms and legs.
  6. Calcium deficiency can cause cramping and change in menstrual flow in women.
  7. Low calcium intakes have also been linked to premature births and some forms of cancer, including colon and breast cancer.
  8. Other ailments which can occur due to calcium deficiency are slow pulse rates, impaired growth, eczema, and insomnia,


Consuming excessive amounts of calcium, especially in the form of supplements can result in a situation called hypercalcemia.  This causes a decreased absorption of other important minerals like zinc, magnesium, iron, phosphorus. Also, excessively high levels of calcium in the body can impair the functioning of kidneys, heart, and arteries.


Most individuals build bone mass only until their mid-30s, after which there is a slow bone loss. This is a natural part of aging, The Bone loss is higher in women, especially after menopause. However, consumption of adequate amounts of calcium, maintaining adequate levels of vitamin D and weight-bearing exercises, help maximize bone strength and bone density. Although it is not possible to build new bone after reaching middle age, it is possible to slow the loss in bone mass with timely care and precaution.

Power Over Pain : Osteoarthritis and Osteoporosis

Bone Health: Build and Maintain Stronger Bones for Life