Calcium (Ca)

It is the most abundant mineral in the body – weighing about 1.5 kg (3.3 lb) in an adult body. Calcium is found in many of the foods we eat – like milk and milk products, beans, nuts, tofu, molasses fruit and green vegetables, yet many people suffer from a shortage of calcium.

on this page

• General
• Daily requirements
• Absorption
• Food sources of calcium
• Calcium supplements
• Osteoporosis
• Muscle spasms
• Other benefits of calcium
• Dangers of excess calcium
• Closing

General

Bones are composed of calcium – but some people have the misconception that once bones are formed that it is the end of the story. That however is not true – as the body can take calcium out of the bones if a deficiency exists, and can later replace it when calcium is once again available in the body.

Approximately 600 mg - 700 mg of calcium enter and leave the bones each day. When calcium is continuously in short supply, the body will keep on withdrawing it from the bones – leading to porous and fragile bones, and that is where the danger lies.

When we talk about a shortage of calcium, the word osteoporosis immediately springs to mind, but that is by far not the full story. A long-term shortage of calcium in the diet can cause various other problems like:

• Rickets
• Osteomalacia
• Abnormal blood clotting
• Abnormal heartbeat
• Abnormal muscle contraction
• Enzyme inactivity

Although the above is a clear indication of how important calcium is to the body, lesser known symptoms of calcium deficiency can include the risk of:

• Tooth decay
• Gum disease
• Deafness
• Toxemia of pregnancy
• Muscle aches and cramps
• Painful and heavy periods
• Cataracts
• Anxiety
• and in children can manifest in impaired growth and behavioral problems

Daily requirements

The older reference of RDA – Recommended Daily dietary Allowance – for adults is 800 mg and 1,200 for pregnant and lactating women.

In August 1997 the Food and Nutrition Board of the Institute of Medicine, National Academy of Sciences (NAS) updated national calcium recommendations for Americans and Canadians and listed the AI (Adequate Intake) as well as the UL (Upper Levels) which is the maximum you should consume daily.

The Adequate intake of calcium is divided into age groups: 1to 3 years 500mg 4 to 8 years 800mg 9 to 18 years 1300mg 19 to 50 years 1000mg 51to 70 years 1200mg 71+ years 1200mg

The calcium UL (Upper levels) of calcium was set at 2500 mg/day for all age groups.

The Food and Nutritional Board found that an estimated 70% of Americans fail to get enough calcium. The most serious deficiency was found amongst adolescent girls ages 11 and older - a time when the body really requires calcium to build bones. It was found that 91% of girls did not meet the AI levels, and 69% of boys were also lacking calcium.

Absorption

Calcium has two other minerals with which it has a love-hate relationship – as they work together, or they can work against one another if there is a huge imbalance between them. These are magnesium and phosphorus. Few people in developed countries have a deficiency of phosphorus as it is supplied more than adequately in our diets and the body easily absorbs it.

Lactose helps with calcium absorption – so taking it with milk may be of further help.

Lifestyle can also influence the absorption of calcium as a sedentary life can lead to impaired absorption. A diet that is very high in fat or protein can also impede calcium absorption and in the elderly, as well as after surgery in younger people, we find that the lack of enough stomach acid contributes to a calcium shortage.

We have listed the effect that a shortage of calcium can have in the body – but we should note that the body needs calcium for blood to clot when an injury is sustained and that it is also required for muscles to contract and relax – as they are a vital part of the biochemical mechanism which cause the proteins myosin and actin to be drawn together.

Certain enzymes in the body – like ATPase, lipase and certain proteolytic enzymes – require calcium to be activated, and a shortage prevents the normal action of these enzymes, and vitamin B12 also requires calcium to be absorbed in the small intestines.

Food sources of calcium

Although we mentioned that green vegetables contain a fair amount of calcium, it is interesting to note that spinach, chard, beet greens and rhubarb are NOT a good source of calcium as they contain oxalic acid which binds to the calcium in these vegetables, making it unavailable to the body.

Vitamin D is very important for the absorption of calcium and 10 minutes of sunshine on the body is enough to manufacture enough vitamin D for proper absorption.

Two cups of milk will supply about 576 mg of calcium and one serving of green leafy vegetables will supply about 44 mg while four slices of enriched white bread would contribute about 84 mg.

Should you have a milk-intolerance, you would have to look at taking a calcium supplement as well as riboflavin and vitamin D to ensure proper absorption.

The same is true if you follow a strict vegetarian diet, which excludes milk and milk products. This may be substituted by soymilk, or the person must ensure that their diet is very high in calcium containing green vegetables.

Calcium supplements

There are a wide variety of calcium supplements available on the market – ranging from inexpensive to very dear. The most important thing about ANY calcium supplement is to look at what amount of “elemental calcium” you derive from the capsule or pill.

The most common forms are calcium carbonate, calcium citrate, calcium citrate malate, calcium gluconate, calcium phosphate and calcium lactate. Regardless of which form of calcium supplement you take – look to see if it states the amount of elemental calcium supplied by the supplement – as that is the important factor.

Manufacturers can source their base ingredient from various origins, but we are of the belief that calcium supplied from oyster shells is the most bio-available form of supplementation.

When buying a supplement made from oyster shells, you however have to ensure that it does not contain any lead, as shells harvested from certain areas could contain unacceptable levels of lead. Our OystaCal is purified to prevent this problem and is therefore safe to use.

The amino acid Lysine is also required for proper absorption but luckily this amino acid is found in many food sources, such as cheese, milk, eggs, fish, red meat and soy products.

Females, which have gone through menopause, need more calcium, as their levels of estrogen are lower – as estrogen helps with promoting the depositing of calcium in the bones.

A diet high in fat, protein or sugar impedes the absorption of calcium while alcohol, coffee, soft drinks (high in phosphorous) junk food, white flour and heavily salted foods leads to a higher loss of calcium by the body.

Although more studies need to be done, it is thought best to take a calcium supplement about 40 minutes before retiring for the night, and since the lactose found in milk helps the utilization of calcium it may be a good idea to have your supplement with a little bit of milk.

Osteoporosis

When calcium is continuously under-supplied the bones become porous and fragile due to continuous withdrawal of calcium – and this then manifests as osteoporosis. The body absorbs calcium far better when the person is younger, yet a supplement in later years can assist to maintain bone density. This de-mineralization of the bone normally occurs later in life, and is far more common in women than men.

It may be accompanied by back pain, due to compression or fracture of the weight bearing lumbar vertebrae.

Muscle spasms

As calcium is required for muscles to contract and release, a shortage of this mineral can lead to muscles spasms.

Other benefits of calcium

It helps to limit the irritation of bile acids in the colon – and by doing that helps to reduce the incidence of colon cancer. Some research also indicates that having enough calcium may help to lower high blood pressure.

When enough calcium is present, the absorption of lead by the body is inhibited but if in short supply the body can absorb this toxic metal and deposit it in the bone.

Dangers of excess calcium

As mentioned before the Upper Levels of calcium is set at 2,500 mg per day and taking massive doses of calcium can lead to kidney stones. Excessively high intake of calcium can also prevent zinc from being absorbed by the body and could also interfere with the metabolism of vitamin K.

Closing

From all the information above we are sure that everybody can understand the importance of calcium in our daily diet, and that this very base mineral is involved in a wide range of body functions, and that a shortage could influence many areas of your general health.

Calcium found in the following Zest for Life products

• Oysta-Cal calcium supplement with vitamin D
• Hair, Nail & Skin supplement - multi nutrient capsules
• Click here to view our full product range.

Nutritional information

Underneath we have information page on vitamins, minerals, amino acids, trace elements, enzymes and various nutritional compounds that can impact greatly on your general health, well-being and longevity. Please note that these pages are for general information only and must not be used to treat or diagnose health concerns.