Calcium - The most abundant mineral in the body
Calcium is the most abundant mineral in the body, making up nearly 2% of total body weight. More than 99% of the calcium in your body is found in your bones, but the other 1% is perhaps just as important for good health. Many enzymes depend on calcium in order to work properly, as do your nerves, heart, and blood-clotting mechanisms.
To build bone, you need to have enough calcium in your diet. But in spite of calcium-fortified orange juice and the best efforts of the dairy industry, most Americans are calcium deficient.1 Calcium supplements are a simple way to make sure you're getting enough of this important mineral.
One of the most important uses of calcium is to help prevent and treat osteoporosis, the progressive loss of bone mass to which postmenopausal women are especially vulnerable. Calcium works best when combined with vitamin D.
Other meaningful evidence suggests that calcium may have an additional important use: reducing PMS symptoms.
Recommended dosages:
- Males and females 9–18 years, 1,300 mg
- 19–50 years, 1,000 mg
- 51 years and older, 1,200 mg
- Pregnant women 1,000 mg (1,300 mg if under 19 years old)
- Nursing women 1,000 mg (1,300 mg if under 19 years old)
To absorb calcium, your body also needs an adequate level of vitamin D.
Milk, cheese, and other dairy products are excellent sources of calcium. Other good sources include orange juice or soy milk fortified with calcium, fish canned with its bones (e.g., sardines), dark green vegetables, nuts and seeds, and calcium-processed tofu.
Many forms of calcium supplements are available on the market, each with its own advantages and disadvantages:
Naturally Derived Forms of Calcium
These forms of calcium come from bone, shells, or the earth: bone meal, oyster shell, and dolomite. Animals concentrate calcium in their shells, and calcium is found in minerals in the earth. These forms of calcium are economical, and you can get as much as 500 to 600 mg in one tablet. However, there are concerns that the natural forms of calcium supplements may contain significant amounts of lead. The level of contamination has decreased in recent years, but still may present a health risk. Calcium supplements rarely list the lead content of their source, although they should. The lead concentration should always be less than 2 parts per million.
Therapeutic Dosages
Unlike some supplements, calcium is not taken at extra high doses for special therapeutic benefit. Rather, for all its uses it should be taken in the amounts listed under Requirements/Sources, along with the recommended level of vitamin D.
It isn't possible to put all the calcium you need in a single multivitamin/mineral tablet, so this is one supplement that should be taken on its own. Furthermore, if taken at the same time, calcium may interfere with the absorption of chromium and manganese. This means that it is best to take your multivitamin and mineral pill at a separate time from your calcium supplement.
Therapeutic Uses
According to most though not all studies, use of calcium (especially in the form of calcium citrate) combined with vitamin may modestly slow the bone loss that leads to osteoporosis.
A rather surprising potential use of calcium came to light when a large, well-designed study found that calcium is an effective treatment for PMS (premenstrual syndrome). Calcium supplementation reduced all major symptoms, including headache, food cravings, moodiness, and fluid retention. It is at least remotely possible that there may be a connection between these two uses of calcium: weak evidence hints that PMS might be an early sign of future osteoporosis.
One small but carefully conducted study suggests that getting enough calcium may help control symptoms of menstrual pain.
Some, but not all, observational and intervention studies have found evidence that calcium supplementation may reduce the risk of colon cancer. Risk reduction might continue for years after calcium supplements are stopped. Individuals who are deficient in calcium may be at greater risk of developing high blood pressure. Among individuals who already have hypertension, increased intake of calcium might slightly decrease blood pressure, according to some but not all studies.
Calcium supplements might slightly improve the cholesterol profile.
One preliminary study suggests that supplementation with calcium and vitamin D may be helpful for women with polycystic ovary syndrome.
Calcium supplementation has also been tried as a treatment to prevent preeclampsia in pregnant women. While the evidence from studies is conflicting, calcium supplementation might offer at least a minimal benefit. The drug metformin, used for diabetes, interferes with the absorption of vitamin B12. Interestingly, calcium supplements may reverse this, allowing the B12 to be absorbed normally. Rapid weight loss in overweight postmenopausal women appears to accelerate osteoporosis slightly, for this reason, taking calcium and vitamin D supplements may be especially appropriate for women on a severe weight-loss diet.
It has been suggested that calcium supplements, or high-calcium diets, may slightly enhance weight loss, but current evidence is inconsistent and overall, more negative than positive.
Finally, calcium is also sometimes recommended for attention deficit disorder, migraine headaches, and periodontal disease, but there is as yet no meaningful evidence that it is effective for these conditions.
Other Important Things to Consider
Purity: Choose calcium supplements with familiar brand names. Look for labels that state “purified” or have the USP (United States Pharmacopeia) symbol. Avoid calcium from unrefined oyster shell, bone meal, or dolomite without the USP symbol, because it may contain high levels of lead or other toxic metals.
Absorbability: Most brand-name calcium products are absorbed easily in the body. If you are not sure about your product, you can find out how well it dissolves by placing it in a small amount of warm water for 30 minutes and stirring it occasionally. If it hasn’t dissolved within this time, it probably will not dissolve in your stomach. Chewable and liquid calcium supplements dissolve well because they are broken down before they enter the stomach.
Calcium, whether from food or supplements, is absorbed best by the body when it is taken several times a day in amounts of 500 mg or less, but taking it all at once is better than not taking it at all. Calcium carbonate is absorbed best when taken with food. Calcium citrate can be taken anytime.
Tolerance: For certain people, some calcium supplements may cause side effects such as gas or constipation. If simple measures (such as increasing your intake of fluids and high-fiber foods) do not solve the problem, you should try another form of calcium. Also, it is important to increase the dose of your supplement gradually: take just 500 mg a day for a week, and then slowly add more calcium. Do not take more than the recommended amount of calcium without your doctor's approval.
Calcium Interactions: It is important to talk with a doctor or pharmacist about possible interactions between your over-the-counter and prescription medications, and calcium supplements. For example, calcium supplements may reduce the absorption of the antibiotic tetracycline. Calcium also interferes with iron absorption. So you should not take a calcium supplement at the same time as an iron supplement - unless the calcium supplement is calcium citrate, or unless the iron supplement is taken with vitamin C. Any medication that you need to take on an empty stomach should not be taken with calcium supplements.
Combination Products
Calcium supplements are available in a bewildering array of combinations with vitamins and other minerals. Calcium supplements often come in combination with vitamin D, which is necessary for the absorption of calcium. However, calcium and vitamin D do not need to be taken together and/or in the same preparation in order to be absorbed by the body. Minerals such as magnesium and phosphorus also are important but usually are obtained through food or multivitamins. Most experts recommend that nutrients come from a balanced diet, with multivitamins used to supplement dietary deficiencies.
Getting enough calcium - whether through your diet or with the help of supplements - will help to protect the health of your bones. However, this is only one of the steps you need to take for bone health. Exercise, a healthy lifestyle, and, for some people, medication, are also important.
Calcium
In this field label scrutiny is a challenge, even for the cognoscenti. Many are not aware of the marked difference between the types of calcium used in the markedly different types? Many comparative studies conducted suggest that calcium citrate is absorbed more efficiently than other forms of calcium.8,9 During and after menopause there is a significant decrease in digestive acid levels, and calcium in its citrate form is able to compensate for this condition, even though it is only 20% elemental calcium, e.g. a calcium tablet manufactured from calcium glaciate is only 9% elemental calcium and is not absorbed as efficiently as one manufactured in the carbonate form which is 40% elemental calcium.
However, any medical condition affecting the kidneys, or hyperparathyroidism, requires the guidance of a physician prior to any form of calcium supplementation. Natural sources of calcium, e.g. oyster shell, bone meal and dolomite have been found to contain slightly higher lead levels than those contained in the refined forms of calcium citrate and calcium carbonate.11 However, recent analysis has indicated only trace levels of lead found in over-the-counter calcium supplements.
Dolomite, Bone Meal or Oyster Shell: These naturally occurring calcium pills may contain heavy metal or lead. At the moment, calcium supplements are not tested by any regulatory agency for lead content. Therefore, it's best to avoid.
Calcium Citrate e.g. Citra cal or Solgar: Calcium is best absorbed in an acidic environment, hence calcium citrate is the best absorbed supplemental form of calcium. It does not require extra stomach acid for absorption; hence we may take it anytime in a day, even on an empty stomach. However Calcium Citrate usually provides less elemental calcium per pill, therefore one may need to take a relatively more numbers of pills per day depending to the needs.
Summary
Calcium is so important in help fighting osteoporosis as all studies state that. It also helps females with PMS, menstrual pain and some studies also say it may reduce the risk of colon cancer and keeping high blood pressure at bay.
According to most though not all studies, use of calcium (especially in the form of calcium citrate) combined with vitamin D may modestly slow the bone loss that leads to osteoporosis.
1000 mg is the recommended dosage for most people and it best absorbed with vitamin D.
Calcium made from oyster shell is one way calcium is sold. There are concerns that the natural forms of calcium supplements may contain significant amounts of lead. The level of contamination has decreased in recent years, but still may present a health risk. Calcium supplements rarely list the lead content of their source, although they should.
Calcium Citrate e.g. Citracal or Solgar: Calcium is best absorbed in an acidic environment, hence calcium citrate is the best absorbed supplemental form of calcium.