Calcium's Importance in Body

Calcium takes its place among the essential elements, numbering 21, that are pivotal for human well-being. However, its capacity to promote health isn't effective when examined in isolation. To exemplify, the body's utilization of calcium relies heavily on maintaining adequate levels of vitamin D.

Two types of calcium are in existence: one firmly bound within bones, while the other, a more accessible variant, resides on the surfaces of bones.

The skeletal system operates as a reservoir of minerals for the body. The lion's share of the body's calcium, approximately 99%, finds its home within bones and teeth, imparting structural support. The remaining 1% is distributed within bodily fluids both within cells and outside them. In instances of low blood calcium levels, the body taps into these reserves within the skeleton, then replenishes bone calcium as required.

A consistent supply of calcium remains indispensable throughout a lifetime, gaining added significance during phases of growth, pregnancy, and lactation.

Calcium assumes a pivotal role in the secretion of hormones and enzymes, facilitating effective neurotransmitter functioning, and contributing to the contraction of muscles and blood vessels.

Within the bloodstream, the concentration of calcium typically ranges from 2.25 to 2.5 mmol. Approximately 40-45% of this quantity forms bonds with plasma proteins, about 8-10% forms complexes with ions like citrate, and roughly 45-50% exists in the form of free ions.

Approximately 10-40% of dietary calcium gets absorbed in the small intestine, a process facilitated by vitamin D. In the presence of a deficiency, the body enhances its absorption of calcium.

In essence, the importance of calcium in the human body transcends its mere presence, encompassing intricate interactions and diverse roles crucial for overall well-being.
Calcium's Importance in Body

Function, deficiency and food sources of calcium

Physical Function
Structural component of bones and teeth; role in intracellular and hormonal secretion regulation, muscle contraction, and activation of some enzyme systems.

Calcium is maintained relatively high concentration in the blood and extracellular fluids, where it is needed to facilitate such functions as blood coagulation and intercellular communications. Blood calcium levels are rigorously controlled so that if blood levels drop the body will rapidly respond by stimulating bone resorption, thereby releasing stored calcium into the blood.

Calcium also enables human blood to clot normally and regulates our muscle contractions, including heartbeat

The most well-known calcium function is to build and strengthen bones and teeth. The calcium in bones serves as a reservoir for calcium that is needed throughout the body. Calcium helps human bones to grow strong until the age of 20-25, when bone density reaches its peak. About 99% of the body’s calcium is stored in bones, and the remaining 1% is found in blood, muscle, and other tissues.

Calcium also is the key factor in normal transmission of nerve impulses. Calcium binds to vesicles that contain neurotransmitters, causing a release into the neural synapses (junction between nerve cells). This allows the flow of ions in and out of nerve cells. If calcium is lacking, nerve-cell function will fail.

Calcium is a key component of the cell membrane and controls cell permeability and electrical properties.

In order to perform daily functions, the body works to keep a steady amount of calcium in the blood and tissues. If calcium levels drop too low in the blood, parathyroid hormone (PTH) will signal the bones to release calcium into the bloodstream.

Deficiency symptoms
A low calcium intake during the growing years limits the bones’ ability to reach their optimal mass and density.

The symptoms of calcium deficiency include rickets, osteomalacia, osteoporosis, scurvy, tetany, parathyroid hyperplasia, stunted growth, laryngospasm.

Deficiency of calcium in young girls causes late puberty, irregular menstruation, excessive bleeding with crampy pain during this period, anemia and lowered state of body resistance against infection.

A more serious deficiency of calcium, called hypocalcemia, results from diseases such as kidney failure, surgeries of the digestive tract like gastric bypass, or medications like diuretics that interfere with absorption.

Food sources
Calcium is found in milk, milk products, sardines, clams, oysters, cheese and dairy foods, dark green vegetables (turnip greens, broccoli, legumes), dried fruits and nuts.

Calcium is classically associated with dairy products: milk, yoghurt and cheeses are rich sources of calcium, providing the major share of calcium from foods in the general diet in the United States and Canada.

When substantial amounts of grains are consumed, for like breads or as maize, these can be important sources, although the calcium in cereals tends to be less bioavailable than that in dairy products.
Function, deficiency and food sources of calcium

Minerals in milk

Minerals represent a small portion of milk (about 8-9 g/L) and they occur in different chemical forms: inorganic ions and salts or as parts of proteins, nucleic acids, fats and carbohydrates. Minerals are constituents of the bones, teeth, soft tissue, muscle, blood, and nerve cells. They are vital to overall mental and physical well-being.

When milk is dried and the residue is burned, a white powder is obtained which is known as ash or mineral part of the milk. The major portion of ash is composed of the chlorides and oxides of potassium, calcium and phosphorus. It is of interest to note that these three elements are in greater concentration in milk than in blood, thus the mammary gland exerts a selective action to concentrate these elements.

The mineral content in milk is influenced by many factors ranging from environmental conditions during pasture, feeding, breeding, stage of lactation and climate to post-milking handling, transportation and processing.

The chemical form of mineral elements found in milk and dairy products is very important due to their absorption in the intestine and biological utilization (transport, assimilation in cells and conversion into biologically active form).

Milk contains more calcium than most foods because of the distribution of calcium in milk. About two thirds of the total calcium in milk is in colloidal form as calcium caseinate, citrate and phosphate; the remaining third is in true solution.

Phosphorus in milk is involved in the stabilization of caseins and is present in two forms: organic and inorganic. Organic P is bound to molecules such as proteins, organic acids, phospholipids and nucleotides, mainly in colloidal phase, and inorganic ionic P is mainly present in soluble fraction.
Minerals in milk

Diet with calcium-rich foods

A calcium-rich diet is recommended for all individuals a part of a healthful, well balanced diet.

Consuming calcium-rich foods daily will help minimize resorption of calcium from the bones and thus promote dense, strong bones.

Calcium is found salmon (with bones), sardines, seafood and dark green leafy vegetables. Milk and dairy products are the primary source of calcium in the North American diet.

Other calcium-rich foods include almonds, asparagus, blackstrap molasses, brewer’s yeast, broccoli, buttermilk, cabbage, carobs, cheese, collards, dandelion green, dulse, figs, filberts, goat’s milk, kale, kelp, milk, mustard greens, oats, prunes, sesame seeds, soybeans tofu, turnip greens, watercress, whey and yogurt.

There are many herbs contains calcium.  This include alfalfa, burdock root, cayenne, chamomile, chickweed, chicory, dandelion, mullein, nettle, oat straw, paprika, parsley, peppermint, plantain, raspberry leaves,  eyebright, fennel seed, fenugreek, flaxseed, hops, horsetails, kelp, lemongrass, red clover, rose hips, shepherd’s purse, violet leaves, yarrow, and yellow dock.

Besides the many supplements or antacids that provide calcium, many food manufacturers have been adding calcium to their foods as well.

Consumption of food with high in protein, fat and/or sugar affects calcium uptake. The average American diets of meats, refined grains and soft drinks leads to increase excretion of calcium.

Consuming alcoholic beverages, coffee, junk foods, excess salt, and/or white flour also leads to the loss of calcium by the body.

Calcium may be poorly absorbed from foods rich in oxalic acid. Oxalic acid can be found in almonds, beet greens, cashews, chard, cocoa, soybeans and spinach. Oxalic acid known as oxalate, is the most potent inhibitor of calcium absorption by binding with it in the intestines and producing insoluble salts that cannot be absorbed.

The normal consumption of foods containing oxalic acids should not pose a problem, but overindulgence in these foods inhibits the absorption of calcium.

Oxalic acid can also combine with calcium to form calcium-oxalate kidney stones. However, that taking magnesium and potassium supplements can prevent the formation of this types of stone.
Diet with calcium-rich foods

Roles of calcium in human body

Human bodies contain more calcium than any other mineral.  Calcium is the fifth most abundant element of the human body. It has a stabilizing function in shells, bones and teeth and in proteins in the extracellular fluid.

Calcium is vital for the formation of strong bones and teeth and for the maintenance of healthy gums.

It is also important in the maintenance of a regular heartbeat and in the transmission of nerve impulses.  The movement of calcium into nerve cells triggers the release of neurotransmitters at the junction between nerves.

Calcium lowers cholesterol levels and helps prevent cardiovascular disease. It is needed for muscular growth and contraction, for the prevention of muscle cramps. It may increase the rate of bone growth and bone mineral density in children.

This important mineral is also plays an essential in blood clotting.  Calcium participates in nearly every steps of the blood clotting cascade. It helps maintain normal blood pressure and prevent bone loss associated with osteoporosis as well. It also helps to prevent cancer.

Calcium provides energy and participates in the protein structuring of RNA and DNA.

It is also involved in the activation of several enzymes, including lipase, which breaks down fats for utilization by the body.

In addition, calcium maintains proper cell membrane permeability, aids in neuromuscular activity, essential to maintain the skin healthy, and protects against the development of preeclampsia during pregnancy.

Adequate calcium intake over one’s lifetime is essential for healthy bones and teeth that will remain strong into old age. Calcium phosphate salts crystalize in a foundation material composed of the protein collagen. The resulting hydroxyapatite crystals invade the collagen and gradually lend more and more rigidity to a youngster’s maturing bones until they are able to support the weight they will have to carry.

Calcium protects the bones and teeth from lead by inhibiting absorption of this toxic metal.
Roles of calcium in human body 

Distribution of calcium in human body

Calcium is the element with the symbol Ca and atomic number 20. It has atomic mass of 40.078 amu.

This mineral is the most abundant electrolyte in the human body, and in healthy adults, accounts for about 2% or 1,300 g, of body weight.

The skeleton is an important reservoir of calcium, serving both a maintain plasma calcium concentrations and to make optimal use of ingested calcium.

Approximately 99% of total body calcium is stored in skeleton and teeth, with many functions and serves also as a structural element in bone.

The rest of the calcium in the body has other important uses, such ‘neurotransmitter release’, muscle contraction and ‘exocystosis’ (a durable process by which a cell directs the contents of secretory vesicles out of the cell membrane).

In the plasma there is also a protein bound calcium fraction, which is present at concentration of 3.2 mg/100 ml (0.8 mmol/l).

About 50% calcium in plasma is ionized and 10% is complexed with citrate phosphate, bicarbonate and lactase.

From birth to approximately 20 years of age, when skeleton reaches its full size and density, calcium content increases by some 40 fold.

Numerous end organs participate in the regulation of calcium. The gastrointestinal tract and kidney, along with bone, are major regulators of calcium balance.

Calcium receptors in the liver may monitor the calcium concentration in plasma, sending signals to the brain and affecting other peripheral sites in the body.
Distribution of calcium in human body

Calcium in human body

Calcium is the most abundant mineral in the human body. The average adult body contains approximately 25000 mmol (1 kg) of which 99% is bound in the skeleton.

The skeleton serves as a bank of minerals for the body. The body can borrow from the skeletal stores when blood calcium levels drop and return calcium to bones as needed. 

In circulating blood, calcium concentration is typically 2.25-2.5 mmol. Approximately 40-45% of this quantity is bound to plasma protein, approx 8-10% is complexed with ion such as citrate and 45-50% is dissociated as free ions.

About 10-40% of dietary calcium is absorbed in the small intestine with the help of vitamin D. The level of calcium absorption from dietary sources drops to 7 in post-menopausal women. The body will absorb more calcium if there is a deficiency.

Numerous end organs participate in the regulation of calcium. The gastrointestinal tract and kidney, along with bone, are major regulators of calcium balance.

Calcium receptors in liver may monitor the calcium concentration in plasma, sending signals to the brain and affecting other peripheral sites in the body.

Calcium has many important functions in the body.
Calcium functions including:

#Calcium is responsible for construction, formation and maintenance of bone and teeth. Bone consists of osteoid, a collagenous organic matrix, on which is deposited complex inorganic hydrated calcium salts know as hydroxyapatites.
#Calcium is a vital component in blood clot formation and also helps in wound healing.
#Calcium helps to control blood pressure, nerve transmission
#Co-factor for enzymes and proteins that regulate digestion, energy, and fat metabolism.
#Calcium helps to transport ions (electrically charged particles) across the membrane.
#Calcium is essential for muscle contraction and relaxation
#Maintain normal heart rhythm
#Calcium assists in maintaining all cells and connective tissues in the body.
#Calcium may be helpful to reduce the incidence of premature heart disease, especially if adequate intakes of magnesium are also maintained.
#Calcium may help to prevent periodontal disease (gum disease).
#Initiation of DNA synthesis
#Cell signaling and neurotransmitter release

Calcium Deficiency 
Calcium deficiency in conjunction with high sodium intake is related to a higher risk of hypertension. The deficiency can lead to loss of calcium from the bone (initially from the jaw and the backbone), which can lead to deformity.

Calcium deficiency also can cause extreme nerve sensitivity, muscle spasms, and leg cramps (called tetany) at very low levels in the blood.
Calcium in human body

The importance of calcium in human body

Calcium is a divalent cation and is the most abundant mineral in the human body. Calcium quantity to be found in an adult’s body is approx 1, 5 kilos. It accounts for roughly 40% of total mineral mass and about 1,5% of total body mass. Calcium is a very potent mineral, fulfilling different tasks in human bodies.

Calcium plays an important role in many biological processes. The most important of its functions relate to: mineralization of the bone tissue (bones and teeth), maintaining the cardiac rhythm, coagulating the blood, regulating the acid-basic equilibrium.

Calcium intake is very beneficial for patients that suffer from acute or chronic convulsions, osteoporosis, concentration disorders, headaches, allergies etc.

Parathyroid hormone restores blood calcium in one of several ways. It can increased the amount of calcium absorbed in the small intestine. It can also stimulate bone destruction.

Calcium levels are also influenced by vitamin D. Vitamin D is available in some foods and also produced in skin when it is exposed to sunlight.

Calcium deficiency leads to anemia, osteoporosis, dental cavities, irregular menses, severe headaches, sexual problems, emotional disorders, sleep disorders (insomnia) and many other dysfunctions.

Calcium nutrition has become a concern for many individuals because of the increased incidence of osteoporosis as human life expectancy continues to increase.

Nutritionally, calcium is found in many foods, but the major spruce in most human diets is dairy products.

In milk, a predominant class of protein is the caseins. Its function is to solubulize calcium phosphate micrograules by surrounding them in a micellar structure, providing an important mineral nutrient in liquid form.
The importance of calcium in human body