Calcium is the most abundant mineral in the body. 99% of the total calcium is stored in the teeth and bones. The rest is found in the bloodstream where it is involved in muscle function, especially the heart, and in muscle control by the nerves. It also plays a role in receiving hormonal messages and blood clotting.
Bone strength and rigidity is due in large part to calcium (in the presence of magnesium and phosphorus).
However, the body can draw calcium from the bones, causing bone fragility.
What does calcium do?
Calcium’s main purpose in the body is to form bone and tooth structure. Calcium also plays a role in:
Adequate Intake (AI)* of Calcium:
Source: Institute of Medicine, Food and Nutrition Board, Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride, 1997.
*Lacking sufficient scientific evidence, authorities have established adequate intake (AI) amounts rather than recommended dietary allowances (RDAs). With regard to calcium in particular, it is very difficult to estimate the intake that will allow for optimal accumulation and retention because a number of other factors affect bone health, including genes, hormones, and physical activity, among others. Adequate calcium intake is based on observed average intakes in North Americans in good health.
Dairy products are the best food sources for calcium. Canned fish is also a good source. Green leafy vegetables like broccoli and cabbage also provide calcium, but in lesser quantity. The calcium in legumes, nuts, and grains is less well absorbed by the intestines than that found in dairy products. Creamy cheeses generally contain less calcium than firm cheeses.
Absorption of the calcium from food depends on what else is eaten at the same meal:
Food Sources for Calcium:
The North American diet typically provides less calcium than the recommended intakes. The percentage of empty calories and processed foods in modern diets and the inadequate consumption of fruits and vegetables are likely the cause.
Calcium deficiency in growing children and adolescents may prevent them from achieving optimal bone mass. Individuals with vitamin D deficiency or chronic kidney failure may have abnormally low blood calcium levels.
Calcium is not well absorbed without the presence of vitamin D. In those over 65, a 400 to 600 IU/day vitamin D supplement is recommended for its beneficial effect on calcium balance and hence bone mineralization. This supplementation is even more important given that the skin’s production of vitamin D decreases with age and less frequent sun exposure.
Calcium deficiency can only be diagnosed through laboratory tests. Observable external signs will only become apparent after a very long time.
Signs of calcium deficiency:
Some people with greater calcium requirements may benefit from taking a supplement:
Signs of excess calcium (at doses higher than 2,500 mg/day):
Increased vitamin D in our bodies may produce a rise in blood calcium levels and lead to heart abnormalities as well as calcium deposits in the kidneys.
You should consult a physician or pharmacist before taking calcium supplements if you:
Natural health products or vitaminic supplements:
A number of medications must be taken two hours before or after a calcium supplement, including:
Calcium requirements may increase when the following medications are taken (nonexhaustive list—consult a physician or pharmacist):
Calcium combined with high doses of vitamin D may interfere with heart and blood pressure medications.
***Speak with your pharmacist if you plan to take calcium supplements. Your pharmacist can help you choose the solution that’s best for you based on your health and any drugs you take.
Calcium, Ca, calcium acetate, Calcium aspartate, calcium carbonate, Chelated calcium, calcium chloride, Calcium citrate, calcium citrate malate, Calcium gluconate, calcium lactate, Calcium lactate gluconate, Calcium orotate, calcium phosphate, Dolomite, Bone powder