CALCIUM

Calcium is the most abundant mineral found in the human body. It represents 52% of the body’s total mineral content and amounts to 1,2% of the total body weight.

Nearly 99% of the total calcium is found in the skeleton. The remaining 1% is equally distributed in the teeth, soft tissues, and extracellular fluid.

Calcium is found in some foods, present in some medicines (such as antacids), and available as a dietary supplement.

Why is calcium essential for the human body?

Calcium is most often associated with healthy bones and teeth, although it also plays a vital role in blood clotting, regulating the heart rhythm, aiding muscles to contract, and controlling nerve functions.

• Calcium and Bone Health: Calcium is well-known for its role in building and strengthening bones. During the formation of the bone, it is an unhardened, protein-rich tissue. Calcium salt deposits gradually crystallize into hydroxyapatite, which makes up about 65% of the bone tissue. When the calcium levels in the body are low, the mineral content of the bone decreases causing the bone to become weak and brittle.
• Calcium and teeth: The calcium-rich hydroxyapatite crystals in the tooth enamel are densely packed, making it the most mineralized tissue (>95%) in the human body. Tooth enamel is extremely strong and durable. The mineralized bone tissue in human teeth is so strong that the back molars can withstand bite forces exceeding 400 pounds of pressure.
• Calcium and nerve conduction: Electrical impulse transmission from one nerve cell to another is transmitted with the help of calcium. It allows the flow of ions in and out of nerve cells. In case of calcium deficiency, the nerve-cell function can fail.
• Calcium and muscle contraction: It helps regulate muscle contraction. When a muscle is stimulated by a nerve, the body releases calcium. This calcium helps the proteins in the muscle to carry out the process of contraction.
• Calcium and blood clotting: Calcium plays an important role in blood clotting. The clotting of the blood is a complex process and involves many enzymes. Calcium has a key role in this clotting process.

The other important functions of calcium are:

– Nerve conduction

– Enzyme regulation

– Lower risk of developing high blood pressure during pregnancy

– Prevents osteoporosis post menopause

What is the Recommended Daily Intake of calcium?

Birth to 1 year: 500 mg/day

1 – 3 years: 400 mg/day

4 – 6 years: 600 mg/day

7 – 9 years: 600 mg/day

10 – 12 years: 600 mg/day

13 to 18 years: 500 mg/day

Adult man: 400 mg/day

Adult woman: 400 mg/day

Pregnant & lactating mothers: 1000 mg/day

Postmenopausal women need at least 1200mg/day of calcium including calcium from diet and supplements. But the calcium intake must not exceed 2000 mg/day.

What are the common signs and symptoms of calcium deficiency?

Blood levels of calcium are tightly regulated. When diet is deficient in calcium, bones release calcium into the blood and usually, no symptoms occur. A more serious deficiency of calcium, called hypocalcemia, can occur due to some conditions like kidney failure and gastric bypass. Certain medications like diuretics can interfere with calcium absorption.

Symptoms of Low calcium (hypocalcemia) are:

– Muscle cramps (usually in the calf muscles)

– Weakness

– Numbness or tingling in fingers

– Abnormal heart rate

– Poor appetite

Calcium deficiency can also occur gradually over a period in people who do not get enough dietary calcium. It may also occur in people who lose more calcium than the body absorbs. 

The first early stage of bone loss is called osteopenia and, if untreated, osteoporosis follows. 

The people who are at risk include:

Postmenopausal women—Menopause lowers the amount of oestrogen in the body, a hormone that helps to increase calcium absorption and retain the mineral in bones. 

Lactose intolerance People who have a difficulty in lactose absorption or are unable to digest lactose (a type of milk sugar) may pose a risk of developing calcium deficiency in the long term. There are non-lactose foods that are high in calcium and can be added to the diet of such people. Click here

What are the sources of calcium?

Plant sources: Ragi, Bengal gram (chana), Horse gram, red kidney beans (Rajma), Soya beans, Moth beans, Amaranth, Fenugreek leaves (methi), Sesame seeds, Tofu (soya paneer), and many more.

Animal sources: Milk, curds, cottage cheese, cheese, prawns, and fish like bacha, katla, mrigal, and rohu.

Does excess calcium cause any health problems?

Excess calcium or hypercalcemia may occur when people take more than 2500 mg of calcium per day from food and supplements. People over the age of 50 should not take more than 2,000 mg daily, especially from supplements. Calcium can block the absorption of other minerals like iron and zinc.

Symptoms of hypercalcemia are:

– Shortness of breath

– Nausea, vomiting

– Irregular heart rate or palpitations

– Weakness, fatigue

– Chest pain

An Interesting fact:

– The bio-availability of calcium differs with the type of dietary source. 

Phytates present in whole-grain cereals inhibit calcium absorption. 

The fermentation process can reduce phytate content and improve calcium absorption.

– Research has proven eating a diet rich in calcium can prevent the formation of kidney stones. The same may not hold true for calcium supplements.