Calcium

Macro Minerals-Major Minerals For The Body

There are some minerals which you need in your diet in amounts greater than 100mg/day. These are called major elements which include Calcium, Magnesium, Phosphorus, Sodium, Potassium, Chloride and Sulphur.

Calcium

Calcium is the most common mineral in the body. It performs many important body functions. Around 99% of total body calcium is stored in the bones and teeth, where it is essential for growth and maintenance. Around 1% is found in the blood, muscle, and cell fluids where it is needed for muscle contraction to make limbs move, heart contraction, blood clotting, secretion of hormones and enzymes, and sending messages through the nervous system.

What are the sources of Calcium?
Calcium is present in both animal and plant foods. The richest source of calcium amongst plant foods are dairy foods (milk, yoghurt and cheese) and amongst the plant foods are green leafy vegetables like amaranth, fenugreek leaves and broccoli. Cereals like Ragi, nuts and seeds like almonds, pistachios and sesame seeds, fishes like salmon, sardines etc. are good sources of calcium.

How much calcium do you need?
Indian Council of Medical Research (ICMR) recommends 600 mg of calcium per day for your children aged from 1 to 9 years of age. The recommendation increases to 800 mg per day for children 10 year onwards and continues to be the same till for adolescents till 17 years of age. Children need more calcium than adults for growing bones.

A normal adult male and female requires 600 mg/day. Calcium RDA increases to 1200 mg/d for pregnant and lactating mothers to meet the increased needs of the baby in the womb and to compensate for calcium secreted in the breast milk.

Some important facts about calcium:

  • Vitamin D is essential for adequate calcium absorption
  • There are some anti-nutritional factors in certain foods which decrease the absorption of calcium. These are oxalates present in green leafy vegetables, horse gram dal, gingelly seeds etc and phytates present in whole cereals. They bind calcium and make it unavailable for absorption
  • When the dietary intake of calcium is low, the release of calcium from bones increases in order to maintain blood levels. If this process continues for long, bones will ultimately become so weak that they may break