We need to consume a certain amount of calcium to build and maintain strong bones and healthy communication between the brain and various parts of the body.
People whose calcium intake is inadequate before the age of 20-25, have a considerably higher risk later on in life of developing brittle bone disease or osteoporosis, because calcium is drawn from the bones as a reserve.
Calcium regulates muscle contraction, including the heartbeat. It also plays a key role in normal blood coagulation (clotting).
Calcium also plays a role in the release of hormones and enzymes, as well as helping blood vessels move blood around the body. A 2010 study carried out in North Carolina State University found that adequate calcium early in life may protect against obesity later on2.
Vitamin D helps our bodies absorb and retain calcium in the bones.
Calcium rich diets increase women's lifespans4 - women whose diets are rich in calcium probably live longer than their counterparts whose diets are low in calcium, researchers from McGill University in Canada reported in the Journal of Clinical Endocrinology and Metabolism.
Which foods are rich in calcium?
The following foods and drinks are rich sources of calcium:
- Seaweeds, such as kelp, hijiki and wakame
- Nuts and seeds, including pistachio, sesame, almonds, hazelnuts
- Dandelion leaves
- Many fortified breakfast cereals
- Many fortified drinks, including soy milk and a variety of fruit juices
- Crushed eggshells - they can be ground into a powder and added to foods and/or drinks
How much calcium should I consume each day?According to the Institute of Medicine (IoM), we should consume calcium daily at the following amounts:
- age 0 to 6 months 200 mg per day
- age 7 to 12 months 260 mg per day
- age 1 to 3 years 700 mg per day
- age 4 to 8 years 1000 mg per day
- age 9 to 18 years 1300 mg per day
- age 19 to 50 years 1000 mg per day
- breastfeeding or pregnant teenager 1000 mg per day
- breastfeeding or pregnant adult 1000 mg per day
- age 51 to 70 years (male) 1000 mg per day
- age 51 to 70 years (female) 1200 mg per day
- age 71+ years 1200 mg per day
Calcium deficiency (hypocalcaemia) and calcium supplements:People with calcium deficiencies are usually advised to take calcium supplements. The supplements should be taken with food for best absorption or to minimize possible undesirable side effects. Each intake of supplements should not exceed 600 mg; if more than that is consumed in one go, the excess will not be absorbed as well.
Calcium supplements should be consumed at intervals spread throughout the day. Vitamin D is added to many calcium supplements, because it encourages the synthesis of proteins in the body which make the absorption of calcium possible.
Choosing the right supplement these days can be confusing; there are various different types in a wide range of combinations and preparations. Which one to select depends on the patient's needs and preferences, their medical condition, and whether they are on any medications.
Elemental calcium, the pure mineral, exists in its natural form with other compounds. Calcium supplements may contain different kinds of calcium compounds and varying amounts of elemental calcium, for example:
- Calcium carbonate contains 40% elemental calcium. This type is more commonly available; it is relatively cheap and convenient. It is absorbed best when taken with food because of its dependence on stomach acids for absorption.
- Calcium lactate contains 13% elemental calcium.
- Calcium gluconate contains 9% elemental calcium
- Calcium citrate contains 21% elemental calcium. This one has the advantage in that it can be taken with or without food, and is absorbed equally well. It is useful for patients with inflammatory bowel disease, achlorhydria and some absorption disorders.
As well as adding vitamin D, calcium sometimes has magnesium added too.
Researchers at Creighton University Medical Center, Omaha, USA, found that calcium supplements increase the risk of developing kidney stones5. Another study carried out in the University of Auckland in New Zealand found that calcium supplements may raise heart attack risk6.
The following conditions, circumstances, or illnesses are known as possible causes of hypocalcaemia (calcium deficiency):
- Bulimia, anorexia and some other eating disorders
- Mercury exposure
- Overconsumption of magnesium
- Long-term use of laxatives
- Prolonged use of some medicines, such as chemotherapy or corticosteroids
- Chelation Therapy used for metal exposure
- Lack of parathyroid hormone
- people who eat a lot of protein or sodium may excrete calcium
- Some cancers
- Postmenopausal women who consume a lot of caffeine, soda or alcohol have a greater risk of having low levels of calcium
- Celiac disease, inflammatory bowel disease, Crohn's disease, and some other digestive diseases.
- Some surgical procedures, including the removal of the stomach
- Kidney failure
- Vitamin D deficiency
- Phosphate deficiency
- Some people who follow a vegan diet may experience calcium deficiency if they do not carefully seek out plant-based calcium rich or calcium-fortified foods
- People who are lactose intolerant may not get enough calcium if they do not carefully seek out non-dairy foods which are rich in calcium or have the mineral added to those foods.
Large doses of calcium from supplements may cause the formation of renal calcium oxalate calculi - which could lead to kidney failure. Consider getting your calcium from natural sources such as broccoli, kale, tofu, and black beans - some of the richest sources of calcium from our food/ Mother Nature.