CALCIUM IN HUMAN NUTRITION

CALCIUM IN HUMAN NUTRITION

Role of Calcium in the Body's Nutrition:

As the most abundant mineral in your body, calcium is essential for your body's overall nutrition and health. Calcium makes up approximately 2.3 percent of your total body weight and contributes to many basic body functions, including disease prevention and absorption of other nutrients. Consuming enough calcium -- between 1,000 and 1,200 milligrams per day for healthy men and women -- is a must for optimal nutrition and health.

Nearly all calcium in the body is stored in bones. Its role is to help bones to remain strong and stiff enough to carry the weight of the body. When needed, the body can draw upon these calcium reserves in the bones and use it elsewhere, such as in the bloodstream and soft tissues.

Calcium is a mineral and so it cannot be produced by the body. Therefore, consuming adequate levels of calcium is crucial. The body needs a constant supply of calcium from diet to keep bones growing and strong. Bone remodelling is an ongoing process in which bone is broken down and calcium is deposited to replace the bone material that is lost. However, when the amount of calcium in the bloodstream is too low, calcium stored in bones is broken down and used in the bloodstream. This may lead to the calcium depletion in bones, a process that can take many years.

During childhood, people undergo a great amount of bone formation. Most individuals can continue to build bone mass until their mid-30s. However, after age 35, they can only slow the bone loss, which is a natural part of aging. Bone loss accelerates especially in women following menopause.

Basic functions of Calcium:

• 99 percent of its calcium to keep your bones and teeth strong, thereby supporting skeletal structure and function. 
• The rest of the calcium in your body plays key roles in cell signalling, blood clotting, muscle contraction and nerve function. 
• Cells use calcium to activate certain enzymes, transport ions across the cellular membrane, and send and receive neurotransmitters during communication with other cells. 
• As an electrolyte, or a particle that helps conduct electricity in the body, calcium is also one of the key players in maintaining a regular heartbeat.

Health benefits of Calcium:

As it was mentioned earlier, calcium’s major role in the body is to help bones grow and to keep them strong. Low rates of calcium intake tend to be highly correlated with low bone mass and elevated bone fracture rates. This mineral is also needed to help teeth develop fully and then to protect them from decay. About 99% of all the calcium in the human body is present in the bones and teeth. The remaining portion is found in tissues and fluids, including the blood. The calcium present in these parts of the body has the following functions:

§  Aids in regulating heartbeat

§  Conducts nerve impulses that send messages through the central nervous system

§  Helps blood vessel and muscle contraction and expansion

§  Lowers blood pressure

§  Regulates fluid balance by controlling the flow of water into and out of the cells

§  Stimulates enzyme and hormone secretion

§  Triggers the formation of blood clots

Recommended dietary allowance for Calcium:

• age 1-3 years: 700 milligrams (mg) per day
• age 4-8 years: 1,000 mg per day
• age 9-18 years: 1,300 mg per day
• age 19-50 years: 1,000 mg per day
• breast-feeding or pregnant teenager: 1,000 mg per day
• breast-feeding or pregnant adult: 1,000 mg per day
• age 51-70 years (male): 1,000 mg per day
• age 51-70 years (female): 1,200 mg per day
• age 71+ years: 1,200 mg per day

Dietary sources of Calcium:

• milk
  
• cheese
• yoghurt
• nuts and seeds, including pistachio, sesame, almonds, and hazelnuts
• beans
• figs
• broccoli
• spinach
• tofu
• many fortified breakfast cereals
• Also, many drinks, including soy milk and a variety of fruit juices are fortified with calcium.

Calcium Absorption:

Factors that facilitate the absorption of calcium include:

• vitamin D and Vitamin K,
• sufficient hydrochloric acid in the stomach,
• small amounts of fat (high fat reduces the availability of calcium),
• exercise,
• magnesium, and
• hormones, including the parathyroid and estrogen hormones.

There are a number of things which work against the absorption of calcium. These include:

• poor absorption of foods, such as in the following conditions:
• pancreatic insufficiency,
• celiac disease,
• other food allergies ,and
• chronic intestinal infections and infestations (such as worms).
• soft drinks,
• high fiber diets,
• coffee,
• oxalic acid,
• phytates,
• excessive amounts of fat,
• sugar, and
• salt.
• Alcohol
• Phytates
• Phosphorus

Calcium Deficiency:

Calcium deficiency simply means that people have inadequate stores of calcium. 

This can result from poor diet, decreased calcium absorption or increased calcium excretion. 

The body’s calcium stores are constantly being depleted through shed hair, skin, nails, sweat, feces and urine. 

Moreover, calcium can only be absorbed in the digestive tract if the body also has an adequate supply of vitamin D.

When calcium levels in the body fall too low, the bones have to supply calcium to tissues and fluids so that normal biological functions can continue. As a result, calcium deficiency can cause the bones to weaken, raising the risk of fracture and increasing the risk of osteoporosis. 

A person will typically not experience any symptoms of calcium deficiency while the body will be depleting the calcium stores in the bones. 

Low blood calcium known as hypocalcemia is usually not caused by a lack of dietary calcium but is a result of other medical conditions or use of medications. 

In extreme cases, hypocalcemia can cause abnormal heart rhythms and may even be fatal.

Minor calcium deficiency symptoms can include:

• Numbness
• Tingling Fingers
• Muscle cramps
• Lethargy
• Poor appetite
• Weak or Brittle fingernails
• Difficulty Swallowing
• Fainting

What are the symptoms and signs of calcium deficiency?

Some of the indications of calcium deficiencies include skeletal abnormalities, such as osteopenia, osteomalacia, osteoporosis and rickets.

Osteomalacia is a failure to mineralize the bone matrix, resulting in a reduction of the mineral content of the bone. In children, osteomalacia is known as rickets. 

When children have rickets, their bones become soft and flexible, bending in ways normal bones would not. 

Features of rickets include bowed legs, beaded ribs, large foreheads, sunken chests protruding chests  and hyper extendable joints.

Osteopenia is the presence of less than normal amount of bone. Osteopenia, if not treated, may result in osteoporosis.

Osteoporosis occurs when the composition of the bone is normal, but the mass is so reduced that the skeleton loses its strength and becomes unable to perform its supporting role in the body. 

In this case, fractures may occur due to minor falls and bumps, or bones may even break under their own weight. 

People with osteoporosis may have a hump in their backs, scoliosis (curvature of the spine), kyphosis (rounded shoulders) or lose height. 

These conditions may be caused by the buckling of their weakened spines, no longer being strong enough to hold the body upright.

Other symptoms of calcium deficiency include:

• insomnia,
• tetany,
• premenstrual cramps, and
• hypertension (high blood pressure).

Low calcium intakes have also been linked to premature births and some forms of cancer, including colon and breast cancer.