Calcium (Ca)


Daily dose

Recommended Daily Allowance, also called Recommended Daily Intake (RDI):

For adults

  • 19 to 50 years old: 1,000 mg per day
  • After the age of 50: 1,200 mg per day (excess calcium intake of more than 1,200 mg per day may increase the risk of heart disease).

Pregnant or breastfeeding women

  • 19 years old: 1,300 mg per day
  • 20 years of age or older 1,000 mg per day

For children

  • 1 to 3 years old: 500 mg per day
  • 4 to 8 years old: 800 mg per day
  • 9 to 18 years old: 1,300 mg per day

Properties

  • Strengthens bones (calcification) and teeth
  • Plays an essential metabolic role in many reactions

Indications

Requirement

  • Muscle problems (tetany)
  • Osteoporosis
  • Rickets in children

During pregnancy, when your body's needs are greatly increased, an imbalance leads to lower bone density in the newborn.

A drop in oestrogen after the menopause, which affects your metabolism, causes osteoporosis.

Excess

  • Mental nervous problems
  • Muscle pain
  • Kidney stones
  • Heart attack, with increased risk of heart attack if you get too much calcium
  • Frequent acidic urination
  • Loss of appetite
  • Vomiting
  • Constipation
  • Stomach pain
  • Tiredness
  • Lightheadedness
  • Heart palpitations
  • Calcification of soft tissues (pancreas, kidneys, corneas, pulmonary alveoli, arteries, etc.)

If you have heart problems, we recommend that you do not exceed 1.0g of calcium per day under the supervision of your doctor. 

Calcium supplements have been linked to an increased risk of prostate cancer. Men who took 400 mg of calcium a day or more had a 51 per cent increased risk of cancer, according to a European study.

Interactions

With plants or supplements

Calcium can interfere with the absorption of iron, zinc, chromium and manganese.

It is recommended to leave 2 hours between taking calcium supplements and these minerals.

This does not apply if you are taking a multivitamin.

It has long been thought that taking calcium and magnesium supplements together may inhibit the absorption of one of these minerals.

Experts now believe that such antagonism, if it exists, has no measurable clinical effect.

With medicines

Several medicines should be taken 2 hours before or after a calcium supplement, including:

  • Quinolone antibiotics and tetracycline derivatives
  • Bisphosphonates (e.g. alendronic acid)
  • Thyroid hormones

You may need more calcium if you are taking the following medicines (this list is not exhaustive, check with your doctor):

  • Thiazide diuretics (Esidrex®, Naturine®)
  • Anticonvulsants (e.g. carbamazepine, phenobarbital)
  • Corticosteroids
  • Isoniazid (anti-tuberculosis)
  • Heparin

Calcium combined with high doses of vitamin D may interfere with beta-blockers (e.g. atenolol, Tenormin®).

Observations

Calcium is absorbed in the gut by vitamin D.

This is why it is recommended to take vitamin D and calcium every day to prevent osteoporosis.

Daily calcium intake through food and/or supplements can have a very positive effect on health.

In addition to preventing osteoporosis, calcium can also (complementarily) treat or prevent high blood pressure, colon cancer, premenstrual tension, reduce obesity, bad cholesterol (LDL), etc.

But be careful not to consume too much calcium, especially if you are at risk of heart disease.

Foods containing calcium

Foods rich in calcium, in descending order of content:

  • Dairy products (milk, cheese, yoghurt)
  • Fish, especially canned fish (with bones)
  • Calcium-fortified soya drinks
  • Oilseeds (sunflower, sesame, etc.)
  • Pulses
  • Nuts
  • Green vegetables (parsley, dandelion, watercress, spinach, fennel, broccoli, green beans, kale, rhubarb, etc.)
  • Plenty of fruit (e.g. gooseberry, orange, blackberry, rhubarb)