Calcium

Description

Calcium is essential for building and maintaining bones and teeth. It is also involved in the proper functioning of the heart muscle, in the transmission of nerve impulses, muscle contractions, coagulation and helps heal wounds.

Calcium is stored in bones. When daily intake is not enough to meet the body’s needs, it draws on its reserves which weakens the bones and increases the risk of fractures. Maintaining an adequate calcium intake, starting early in life, maximizes bone mass and helps reduce bone loss provided intake is maintained throughout life.

An adequate intake is particularly important during pregnancy, to prevent or treat osteoporosis and when taking corticoids.

When taken with potassium and magnesium, calcium helps control blood pressure. A diet rich in calcium reduces symptoms associated with premenstrual syndrome and slightly reduces the risk of developing colon cancer.

Sources

Milk and dairy products are an excellent source of calcium. Milk is also fortified with vitamin D, a nutrient that helps the body use calcium. Calcium-enriched drinks are also available.

Calcium is also found in dark green vegetables (broccoli), sesame seeds, almonds and nuts, canned fish (sardines, salmon, tuna), seafood (clams, oysters), legumes and tofu.

Approximate Calcium Content
 Food  Portion  Content
 Almonds and Brazil nuts 125 mL 206 mg
 Apple compote 250 mL 50 mg
 Baked beans (canned) 30 g 138 mg
 Beef liver 250 mL 218 mg
 Brick cheese, cheddar, swiss 45 g 315 mg
 Broccoli 125 mL 90 mg
 Cabbage, cooked 125 mL 84 mg
 Chocolate milk 250 mL 300 mg
 Cottage cheese 170 g 98 mg
 Cream cheese 28 g 23 mg
 Dried figs 125 mL 135 mg
 Egg 1 28 mg
 Firm tofu, plain 100 g 205 mg
 Ice cream 250 mL 194 mg
 Food  Portion  Content
 Ice milk 125 mL 135 mg
 Legumes 250 mL 135 mg
 Milk-based soup 250 mL 190 mg
 Milk 250 mL 315 mg
 Mozzarella, blue, feta cheeses 45 g 225 mg
 Orange 1 52 mg
 Pasteurized cheese 1 slice 188 mg
 Pie d’Angloy cheese 250 mL 212 mg
 Salmon (canned with bones) 79 g 180 mg
 Sardines (canned with bones) 90 g 360 mg
 Soft ice cream 250 mL 253 mg
 Spinach 125 mL 129 mg
 Yogurt (assorted flavours) 175 g 270 mg
 Yogurt drink 175 g 186 mg

Oxalate-rich foods such as rhubarb, spinach and beets should be eaten in moderation since they inhibit the absorption of calcium.

In some cases, vitamin D supplements may be necessary to increase calcium absorption.

Recommended Daily Allowance (RDA)

Recommended average daily nutrient intake that is sufficient to meet the nutrient requirements of nearly all (97 to 98%) healthy individuals in each age and gender group. The RDA should only be used as a guide for daily individual intake.

Calcium Requirements
 Age  Men   Women 
 1-3 years 700 mg 700 mg
 4-8 years 1000 mg 1000 mg
 9-13 years 1300 mg 1300 mg
 14-18 years 1300 mg 1300 mg
 Age  Men   Women 
 19-50 years 1000 mg 1000 mg
 51-70 years 1000 mg 1200 mg
 > 70 years 1200 mg 1200 mg
 Pregnancy and breastfeeding > 18 years   1000 mg

The recommended daily intake, according to the Osteoporosis Canada, is 1200 mg of elementary calcium per day for men 50 years of age and older.

Deficiency

Abnormally low blood calcium can cause dizziness, irritability, tetany, tremors and cardiac arrhythmia. Simple dietary calcium deficiency does not produce any of these symptoms.

Chronic deficiency increases the risk of osteoporosis, osteomalacia, colon cancer and hypertension.

The body stores approximately 1 kg of calcium which is enough for several years. More than 99% of total body calcium is stored in the bones and teeth. If a person did not have any calcium whatsoever in his diet, he would lose 20% of his reserves over 6 years, based on a loss of about 100 mg per day…

Toxicity

Abnormally high blood calcium can lead to loss of appetite, confusion, delirium and coma. Excessive consumption of calcium does not produce any of these symptoms.

Supplements

Some people may require calcium supplementation even though their calcium intake from food is sufficient.

Taking calcium supplements during pregnancy could help reduce the risk of hypertension and preeclampsia. Women at risk should take at least 1500 mg of elementary calcium per day and even 2000 mg per day. Medical monitoring is recommended.

Caution is recommended for those taking calcium supplements and suffering from kidney stones, dehydration, hypercalcemia, hypophosphatemia, kidney failure or sarcoidosis.

Calcium content varies based on the type of salt used.

Calcium Content Based on Salt Used
 Age  Percentage 
 Carbonate 40%
 Chloride 27.2%
 Citrate 21.%
 Glucoheptonate 8%
 Age  Percentage 
 Gluconate 9%
 Lactate 13%
 Dibasic phosphate 23%
 Tricalcium phosphate 39%

For example, a 1250 mg calcium carbonate tablet contains 500 mg of elementary calcium.

Carbonate and calcium gluconate should be taken with food, whereas calcium phosphate should, ideally, be taken on an empty stomach.

Watch what you eat. Diet has a significant impact on health!