Calcium Requirement

Calcium Requirement: Overview

Calcium is the most abundant mineral in the human body.  Of the body's total calcium, about 99% is in the bones and teeth where it plays a structural role.  The remaining 1% is present in body tissues and fluids where it is essential for cell metabolism, muscle contraction and nerve impulse transmission. The main function of calcium is structural.  The skeleton of a young adult male contains about 1.2kg of calcium.  There is continuous movement of calcium between the skeleton and blood and other parts of the body.  This is finely controlled by hormones.  Metabolites of Vitamin D are important in this, increasing reabsorption of calcium by bones.

Calcium also plays a role in cell biology.  Calcium can bind to a wide range of proteins altering their biological activity.  This is important in nerve impulse transmission and muscle contraction.  Calcium is also needed for blood clotting and activating clotting factors.

Contributing Risk Factors

Some research has indicated that vegetarian women are at less risk of osteoporosis than are omnivorous women.  This is thought to be due to animal protein increasing calcium loss from bones.  However, other research has found no difference between vegetarians and omnivores.

Signs and Symptoms

A low level of calcium in the blood and tissues can cause hypocalcemia.  This involves sensations of tingling and numbness and muscle twitches.  In severe cases muscle spasms may occur, called tetany.  It is more likely to be due to a hormonal imbalance in the regulation of calcium rather than a dietary deficiency.

Excess calcium in the blood can cause nausea, vomiting and calcium deposition in the heart and kidneys.  This usually results from excessive doses of vitamin D and can be fatal in infants.

Treatment and Prevention

People aged 19 to 50 should be getting 1000mg of calcium per day in the form of low oxalate greens, fortified foods or dairy products.  Put another way, if you are aged 19-50 and are not drinking three cups of calcium-fortified soy milk, orange juice or milk, or eating three cups of greens every day then you should consider taking calcium supplements.

During pregnancy, calcium absorption from the gut increases and no additional calcium is generally needed.  Pregnant adolescents are an exception to this, having particularly high calcium needs.  Breastfeeding women need an extra 550mg of calcium daily; a lactating woman can lose up to 300mg per day in breast milk.

The NIH recommends a calcium intake of 1000mg per day for pre-menopausal women and post-menopausal women on estrogen replacement therapy (ERT).  If post-menopausal women are not on ERT, their calcium intake should be 1500mg per day.

Calcium absorption decreases with age so it is important that the elderly receive adequate dietary calcium.

Additional Tips:
  • Calcium should ideally be obtained through our diet.  Dairy products are particularly high in calcium and a glass of milk contains about 300mg calcium.
  • However, if women are unwilling or unable to obtain enough calcium in their diet, they might consider calcium supplements.
  • There are a large variety of calcium supplements available, and if you are searching for one, you should keep in mind the following:
     
    • Look for supplements that contain calcium carbonate because they contain the highest percentage of calcium per tablet, are cheaper, and are more widely available.
    • Beware of supplements made of dolomite (limestone) or bone meal because they may be contaminated with lead.
    • There is no advantage in taking supplements that are chelated (bound) with protein.
    • The vitamin D in some supplements is usually not necessary because we normally get enough vitamin D from sunlight, fortified milk and eggs.
  • Try to keep total calcium consumption under 2000mg per day.  At higher amounts, there is an increased risk of developing kidney stones.
  • To increase the absorption of calcium take smaller amounts more often, such as at meal-times, ratheer than taking one big dose.
  • Beware that calcium supplements can decrease the amount of iron you absorb.

Complications

Vitamin D is needed for absorption of dietary calcium and so calcium deficiency may be linked to rickets in children.  In adults, calcium deficiency may lead to osteomalacia (softening of the bones).  This may be related to repeated pregnancy with lengthy breast feeding.

Osteoporosis can be due to calcium deficiency.  This involves loss of calcium from the bones and reduced bone density.  This causes bones to be brittle and liable to fracture.  Bone loss occurs with age in all individuals.  This usually occurs after 35-40 years and involves the shrinking of the skeleton.  Bone loss is greatest in women following the menopause.  This is due to reduced levels of the hormone, estrogenPostmenopausal women are particularly at risk from osteoporosis.

Calcium Need

Information On This Page

Signs, symptoms & indicators of Calcium Requirement:

Symptoms - Food - Preferences

Fatty food craving may be a sign or symptom of Calcium RequirementFatty food craving
A calcium deficiency can cause various food cravings, including a craving for fats and oils.

Symptoms - Nails

Conditions that suggest Calcium Requirement:

Dental

Bruxism (Clenching/Grinding Teeth) often suggests Calcium RequirementBruxism (Clenching/Grinding Teeth)
Cheraskin & Ringsdorf (1970) studied the effects of nutritional supplements on teeth grinders or clenchers.  Of these, 16 took calcium, vitamin A, vitamin C, Vitamin B5 (pantothenic acid), iodine, and vitamin E.  When surveyed a year later, they reported that bruxism vanished.  In contrast, the 15 bruxers who only took vitamins A, C, E and iodine showed no improvement.  It seemed reasonable to conclude that the active agents were calcium and pantothenic acid (vitamin B5).

Musculo-Skeletal

Osteoporosis - Osteopenia often suggests Calcium RequirementOsteoporosis - Osteopenia
When body stores of calcium are low, the body must draw calcium from the bones in order to avoid serious complications.

Reproductive

Postmenopausal Issues often suggests Calcium RequirementPostmenopausal Issues
Postmenopausal women generally need more calcium and magnesium.

Skin-Hair-Nails

Male Hair Loss often suggests Calcium RequirementMale Hair Loss
See the link between Hair Loss and Manganese.

Risk factors for Calcium Requirement:

Environment / Toxicity

Magnesium Toxicity increases risk of Calcium RequirementMagnesium Toxicity
Calcium and magnesium levels need to be maintained in balance since they have an antagonistic relationship.  An excess of one implies a need for the other to maintain balance.

Supplements and Medications

Regular osmotic laxative use often increases risk of Calcium RequirementDaily/excessive/regular osmotic laxative use
Oral osmotic laxatives often contain magnesium which reduces calcium absorption.  The long-term use of such products may result in a calcium deficiency.
Much magnesium supplementation often increases risk of Calcium RequirementMuch magnesium supplementation
A high intake of magnesium might impair absorption and use of calcium.
Counter-indicators:

Symptoms - Food - Beverages

(High/moderate) soft drink consumption often increases risk of Calcium Requirement(High/moderate) soft drink consumption
The carbonation in soft drinks causes calcium loss in the bones through a three-stage process:
  1. The carbonation irritates the stomach.
  2. The stomach "cures" the irritation the only way it knows how.  It adds the only antacid at its disposal: calcium.  It gets this from the blood.
  3. The blood, now low in calcium, replenishes its supply from the bones.  If it did not do this, muscular and brain function would be severely impaired.
But the story doesn't end there.  Another problem with most soft drinks is that they also contain phosphoric acid (not the same as the carbonation, which is carbon dioxide mixed with the water).  This substance also causes a drawdown on the store of calcium.

Soft drinks soften your bones (actually, they make them weak and brittle) in three ways:
  1. Carbonation reduces the calcium in the bones.
  2. Phosphoric acid reduces the calcium in the bones.
  3. The beverage replaces a calcium-containing alternative, such as milk or water.  Milk and water are not excellent calcium sources, but they are sources.
(High) coffee consumption may increase risk of Calcium Requirement(High) coffee consumption
Research has shown that drinking coffee causes a significant loss of several vitamins and minerals, including vitamins B and C, calcium, iron, and zinc.

Symptoms - Food - Intake

Some dark leafy greens consumption often increases risk of Calcium RequirementLow/no/some dark leafy greens consumption
Those aged 19 through 50 who are not getting at least 1000mg of calcium per day through low oxalate greens, fortified foods such as orange juice, soy milk or dairy products probably have a calcium requirement.

Symptoms - Gas-Int - General

Symptoms - Skeletal

Calcium Requirement can lead to:

Nutrients

Recommendations for Calcium Requirement:

Diet

Increased Fruit/Vegetable Consumption is highly recommended for Calcium RequirementIncreased Fruit/Vegetable Consumption
Dark green leafy vegetables and broccoli are rich in calcium.
Caffeine/Coffee Avoidance is highly recommended for Calcium RequirementCaffeine/Coffee Avoidance
Research has shown that drinking coffee causes a significant loss of several vitamins and minerals, including vitamins B and C, calcium, iron, and zinc.

Mineral

Calcium is highly recommended for Calcium RequirementCalcium
Calcium supplements are best taken between meals, ideally right before bed.  Since you can only absorb about 500mg at a time, you may want to use divided doses.  Drink a full glass of water or juice with them.  The form of calcium does not really matter – calcium carbonate or calcium citrate – just don't use the dolomite form, which may be contaminated with lead.  Some people simply take generic TUMS, which is fine.  Studies show that calcium carbonate works just as well as the high profit margin supplements that you can buy.

NOTE: Calcium supplements may interfere with prescription medications or other supplements that you are taking, so try to avoid taking them within a few hours of any other pills.

Vitamins

Vitamin D is highly recommended for Calcium RequirementVitamin D
Vitamin D is essential for absorption of calcium from the gut.  This is because calcium is transported into the body by a special carrier protein which requires vitamin D for its synthesis.

KEY

Weak or unproven link: may be a sign or symptom of; may increase risk of
Weak or unproven link:
may be a sign or symptom of; may increase risk of
Strong or generally accepted link: often suggests; often increases risk of; often leads to
Strong or generally accepted link:
often suggests; often increases risk of; often leads to
Definite or direct link: increases risk of
Definite or direct link:
increases risk of
Strong counter-indication: often decreases risk of
Strong counter-indication:
often decreases risk of
Very useful: is highly recommended for
Very useful:
is highly recommended for