Calcium Functions

Calcium plays multiple important roles in helping to keep the body functioning smoothly and efficiently.  Even as children, we learn that for proper growth and strong, healthy bones we need to consume a diet rich in calcium. We are told to drink a full glass of milk with every meal every day because milk is an excellent source of calcium. The information about calcium being essential for growth is correct, but the vital contribution that calcium makes to overall health goes beyond bone health as it plays a vital role in heart, muscle and nerve function.  

The primary function of calcium is to maintain healthy bones and teeth, and it remains crucial in all stages of life, even old age. Many adults assume that because they have stopped growing in height, they no longer need to pay attention to the amount of calcium in their diet. But that is far from the case. Calcium absorption tends to become less effective with age, the likelihood of deficiency increases. Calcium deficiency in the elderly can be very damaging. Calcium deficiency can lead to increased susceptibility to bone fractures and dental problems such as teeth falling out.  In serious cases, the impact on the body’s functioning can be more pervasive, even life threatening.

Fun Factoids

• Calcium, the element in the periodic table with the symbol Ca, is the 5th most abundant element in the earth’s crust.

• Calcium is never found naturally in its pure form. It is always combined with other elements.

• The word “calcium” is derived from the Latin word “calcis” which means “lime.” Calcium is extracted from limestone, marble, and chalk.

• Since ancient times, and continuing today, calcium has been widely used in construction. The Egyptians used limestone (crystallized calcium carbonate) to build pyramids. Many of today’s homes are built using concrete or cement made from lime (calcium oxide).

• Prior to the invention of electricity, calcium oxide, or lime, was used to light the stage in theaters, which explains the origin of the phrase “in the limelight.”

• Calcium is the most abundant metallic element in the human body. The average adult body contains about 2 lbs. of calcium, 98% of which is stored in the bones and 1% in the teeth. The remaining calcium absorbed by the body is used to facilitate blood clotting, muscle contraction, and nerve conduction.

• Calcium is necessary, not only for healthy bones and teeth, but also for proper functioning of muscles, nerves, and blood vessels. Without calcium, muscles cannot contract, and any form of exercise would result in early fatigue. Calcium also activates the release of important neurotransmitters so that the brain can communicate effectively with every part of the body. Calcium even helps transport other nutrients through cell membranes so they can perform their necessary functions. Another very important function of calcium is to enable blood clotting, which prevents the body from losing too much blood after a serious injury.

• Vitamin D is essential for the proper absorption of calcium.

• Milk and milk products are commonly known as one of the best ways to ensure getting plenty of easily-absorbed calcium in the daily diet. Other very good sources of calcium are orange juice fortified with calcium and vitamin D, broccoli and cauliflower, soybeans and tofu, canned salmon and sardines (with the bones), nuts, sunflower and sesame seeds, and molasses.
• The recommended daily allowance for calcium for adults is 1,000 to 1,200 mg. The upper tolerable limit is 2,500 mg. Either too little or too much calcium in the diet can lead to serious health problems.

• The ability to absorb dietary calcium declines with age. Children typically absorb 50 to 70% of the calcium they ingest, while adults only absorb 30 to 50% and older adults probably even less. The fact that an individual has stopped growing does not stop the body’s continuing need for calcium.

• When the level of calcium in the blood drops below the normal level of 10 mg per 100 ml, the parathyroid glands secrete additional parathyroid hormone which causes the needed calcium to be released from the bones. The calcium blood level returns to normal, but the bones become weaker. As this demineralization process continues, the loss of bone mass could lead to the serious condition known as osteoporosis.

The following are some of the other important functions of calcium that are effected by calcium.

  • Enabling blood clotting

  • Transmitting and receiving nerve signals

  • Contracting and relaxing muscles

  • Releasing hormones and other chemicals

  • Facilitating the absorption of other nutrients

  • Maintaining a normal heartbeat

Calcium can help prevent or lower the risk of developing colon cancer, osteoporosis, and Type 2 diabetes. While the efficacy of calcium in preventing heart disease is equivocal, there is evidence that in individuals with high blood pressure, a high calcium intake can help lower their systolic pressure. In addition, calcium supplements are sometimes prescribed to relieve menstrual cramps, as well as leg and foot cramps. Calcium may even help relieve headaches, irritability, insomnia, and depression brought on by menopause.

Drug and Food Interactions

As with any drug/food interaction you should always consult your physician, as it is the safest and most accurate way to determine if there is a possible interaction. also provides reliable resources.