Calcium is a mineral that is abundantly found in our body. A major part of it is in the teeth and bones and it is responsible for giving strength and resilience to these structures. The rest is found in nerve cells, body tissues, blood, and other body fluids. Calcium plays a very important role in the body’s overall health and nutrition as it contributes to many basic body functions like bone mineralization, nerve conduction, contraction and relaxation of heart and skeletal muscles etc. Maintaining a proper level of calcium in the body is essential for building strong bones and teeth; clotting blood; sending and receiving nerve signals; squeezing and relaxing muscles; releasing hormones and other chemicals; and keeping a normal heartbeat.
Our body regulates the level of calcium available in the blood in a narrow range to ensure healthy functioning of nerves and muscles through various hormones. However the main substances involved in the regulation of calcium and phosphorus levels are vitamin D and parathyroid hormone. Since calcium is stored primarily in the bones and teeth, these organs are the ones affected the most when we do not have adequate calcium in the body.
Sources of Calcium
Our body does not produce calcium, so one must get it through external sources. Popular food sources for calcium are dairy products. The body can easily absorb the calcium found in milk, yogurt, cheese and buttermilk. Phosphorous and magnesium help the body to absorb and use calcium effectively and these two are also found in milk.
Other non-dairy sources of calcium include green leafy vegetables such as spinach, cauliflower, broccoli, turnip greens, mustard greens, and cabbage; fish like salmon and sardines, seeds and nuts like sunflower seeds, almonds, etc.
Calcium is often added to some natural food products like orange juice, soy milk, breads, and tofu. These can be an excellent source of calcium for people who do not prefer dairy products in their diet.
Adequate absorption of calcium requires exposure to sun in addition to diet. UV radiation from the sun helps in converting vitamin D in our body to its active form, which is required for calcium regulation.
Who should take calcium supplements?
People usually get the required amount of calcium through diet as long as it is balanced and incorporates some dairy and non dairy sources of calcium. However, in certain cases, where access to a good diet is unavailable or in people who lead a very sheltered life or in climates without adequate exposure to sun, calcium deficiency may occur. People with lactose-intolerance (trouble in digesting the sugar in the milk) may not be able to ingest dairy products and hence not get enough calcium.
When the calcium intake is insufficient, the body uses up the calcium from your skeleton, thereby making them weak and brittle, a condition known as osteoporosis. More severe deficiency of calcium leads to conditions called osteomalacia and tetany, where bones become soft and fracture easily and painful contractions of muscles occur and death may occur due to abnormality in heart conduction.
Women are considered to be at a higher risk of osteoporosis due to sheltered and sedentary lifestyles along with hormonal changes following menopause (Cessation of menstrual periods). So generally older women after menopause, people who are not maintaining a balanced diet, or who are unable to maintain a balanced diet for some dietary or other health reasons, people on a vegan diet; or people whose body is not able to absorb enough calcium due to other health problems; people diagnosed with osteoporosis; and people on a high-protein or high-sodium diet which may cause your body to excrete more calcium, are recommended to take calcium supplements.
What calcium supplements to take?
Calcium supplements come in many forms, either as pure calcium salts or in combination with other minerals and vitamins. A common and popular combination is calcium with vitamin D products. To choose the right supplement one should be aware of the required daily recommendation (RDA levels) for age and gender and whether there are any other accompanying mineral or vitamin D deficiency.
It is better to take calcium supplements between meals so it is less likely to inhibit the absorption of other vital nutrients. A recommendation for daily calcium requirement is as below. However, this should be interpreted in the context of any prevailing deficiencies and co-existing health conditions.
|Age group||Calcium Intake/day|
*For pregnant women, calcium intake is 1,300 mg/day
*Source: INSTITUTE OF MEDICINE OF THE NATIONAL ACADEMIES