The role calcium plays in maintaining the function of your cells is so vital that your body will remove it from your bone to maintain adequate blood levels when calcium dips too low. Calcium is the most prevalent mineral in your body, 99 percent of which is stored in your bones. The remaining 1 percent is maintained in a delicate balance within your bloodstream and soft tissue. Include plenty of calcium-containing foods in your diet to ensure you get enough of this crucial mineral.
Calcium and Muscle Cells
One of the main functions of calcium is to help facilitate the contraction of muscle cells. There are three different types of muscle cell--smooth muscle, skeletal muscle and heart muscle. Smooth muscle lines your blood vessels and digestive system, skeletal muscle attaches to your bones and heart muscle keeps your heart beating. Calcium normally exists outside your muscle cells. When your muscle cells receive a signal to contract, a calcium channel opens within the cell membrane, allowing calcium ions to enter. These calcium ions bind to troponin-C, a protein, which initiates the contraction of your muscle.
Calcium's Effect on Nerve Cells
Calcium is also involved in the conduction of nerve impulses that are sent to muscle cells, signaling them to contract. Nerve impulses travel down the membrane surfaces of your nerves in less than a millisecond. During nerve transmission, the calcium channel works in essentially the same fashion as it does for muscle contraction. As the nerve impulse progresses, the calcium channel is activated, allowing an influx of calcium ions into your nerve cell. The presence of calcium signals your nerve cells to release acetylcholine, a neurotransmitter, into the space between cells to keep the impulse going.
Calcium's Role in Blood Clotting
Blood clotting is a complicated process called the clotting cascade, which occurs via two distinct pathways, requiring the presence of calcium for several steps. It is referred to as a cascade because each step signals the initiation of the next step. The first signal in the clotting cascade is injury to one of your blood vessels, which causes bleeding. From there, your blood platelet cells adhere to the wound to begin clot formation and prevent blood loss. According to Union County College, clot formation relies on 11 clotting factors and the presence of calcium, referred to as factor IV in the clotting cascade.
Getting Enough Calcium
Maintain your calcium levels by including calcium-containing foods in your diet. Dairy foods such as milk, cheese, yogurt and cottage cheese are all high in calcium. Fruits and vegetables containing calcium include oranges, kiwi, spinach, kale and broccoli. Other dietary sources of calcium are tofu, navy beans, chickpeas and lentils, as well as fortified foods, such as breakfast cereals and soy milk. Oregon State University says adults need at least 1,000mg of calcium daily from age 19 through 50; women over 50 and men over 70 require 1,200mg. Children aged 4 to 8 years require 1,000mg, children from 1 to 3 years need 700mg and adolescents need 1,300mg per day.
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