Calcium is a mineral most often associated with healthy bones and teeth, although it also plays an important role in blood clotting, helping muscles to contract, and regulating normal heart rhythms and nerve functions. About 99% of the body’s calcium is stored in bones, and the remaining 1% is found in bloodstream, muscle, and other tissues.

In order to perform these vital daily functions, the body works in order to keep a steady amount of calcium in the blood plus tissues. If calcium levels drop too low in the blood, parathyroid hormone (PTH) will signal the bones to release calcium into the bloodstream. This hormone may also activate vitamin D to improve the particular absorption of calcium within the intestines. At the same time, PTH signals the kidneys to release less calcium mineral in the urine. When the body has enough calcium, the different body hormone called calcitonin works in order to do the opposite: it lowers calcium amounts within the blood by stopping the release associated with calcium from bones and signaling the kidneys to rid more of it in the particular urine.

The particular body gets the calcium it needs in two ways. One is by eating foods or supplements that contain calcium supplement, as well as the other is by drawing through calcium in the entire body. If one does not eat enough calcium-containing foods, the body will remove calcium supplements from bones. Ideally, the particular calcium that is “borrowed” from the bones will be replaced at a later point. But this doesn’t always happen, plus can’t always be accomplished just by eating a lot more calcium.

Recommended Amounts

The Recommended Dietary Allowance (RDA) for calcium for women 19-50 years of age is 1, 000 mg daily; for women 51+, 1, 200 mg. For pregnant and lactating ladies, the RDA is one, 000 magnesium. For men 19-70 many years of age, the RDA is 1, 000 mg; for men 71+ years, one, 200 magnesium. [1]

Calcium mineral and Health

The reviews below specifically looked at the effect of calcium on various health conditions. Scroll down for links to more information on the particular health effect of specific foods rich in calcium.

Food Sources

Calcium is usually widely available* in many food items, not just milk along with other dairy foods . Fruits, leafy greens, beans, nuts, and some starchy vegetables are good sources.

*Bioavailability of calcium supplements

Calcium is a large mineral and not so easy to break straight down in the gut. The particular amount of calcium listed on the particular Nutrition Facts label associated with a food product is the measure of calcium in the meals, but not necessarily the amount the particular body will absorb. The amount that is definitely actually assimilated and used by the body is called “calcium bioavailablity. ” Some meals have higher calcium bioavailability than others.

For example , dairy foods have a bioavailablity of about 30% absorption so if a food label on milk lists 300 mg of calcium mineral per cup, about 100 mg is going to be absorbed and used simply by your body. Plant foods like leafy greens contain less calcium overall but have got a higher bioavailability than dairy. For instance , bok choy contains about 160 magnesium of calcium supplement per 1 cup cooked but has the higher bioavailability of 50%, so regarding 80 mg is soaked up. Therefore , consuming a single cup associated with cooked bok choy has almost while much bioavailable calcium because 1 mug of whole milk. Calcium-fortified orange juice plus calcium-set tofu have a similar total amount of calcium supplements and bioavailability as milk products, while almonds have slightly lower total calcium and bioavailability of about 20%. This may be useful information for those who cannot eat dairy products foods or even who follow a vegan diet plan.

A downside to some plant foods is that they contain naturally occurring plant substances, sometimes referred in order to as “ anti-nutrients . ” Examples of anti-nutrients are usually oxalates plus phytates that bind to calcium and decrease its bioavailablity. Spinach contains the most calcium of all the green greens from 260 mg of calcium mineral per one cup cooked, but it is also high in oxalates, lowering the particular bioavailability so that only 5% or about 13 magnesium of calcium supplement can become used with the body. The takeaway message is not really to avoid spinach, which contains other valuable nutrients, yet not in order to rely upon spinach since a significant source associated with calcium since most of this will not be consumed by the body. You can also schedule your meals so that you do not really eat “calcium-binding” foods like spinach with the same meal as calcium-rich food items or along with supplements.

In case you are scanning foods labels to reach a specific amount of daily calcium supplements, continue to aim for the particular RDAs set for your own age group plus gender. The particular RDAs are usually established with an understanding of calcium bioavailability in food. Also keep in mind that the exact amount of calcium absorbed in the body will vary amongst individuals based on their metabolism and what other foods are eaten at the same meal. In general, eating a variety associated with calcium-rich meals can help to offset any small losses.

Signs of Deficiency and Toxicity


Blood levels of calcium are tightly regulated. Bones will launch calcium into the blood if the particular diet does not provide enough, and no symptoms usually occur. A more serious deficiency of calcium, known as hypocalcemia, results from diseases such as kidney failure, surgeries of the digestive tract like gastric bypass, or medications want diuretics that will interfere along with absorption.

Symptoms of hypocalcemia:

  • Muscle cramps or even weakness
  • Numbness or tingling in fingers
  • Abnormal heart rate
  • Poor appetite

A gradual, progressive calcium deficiency can occur in people who also do not get enough dietary calcium mineral within the long-term or whom lose the ability in order to absorb calcium supplement. The first early stage of bone loss is called osteopenia and, if untreated, brittle bones follows. Examples of individuals at risk include:

  • Postmenopausal women —Menopause reduces the quantity of estrogen in the body, the hormone that helps to increase calcium assimilation and retain the mineral within bones. Sometimes physicians may prescribe hormone replacement treatment (HRT) with estrogen plus progesterone to prevent osteoporosis.
  • Amenorrhea —A condition where menstrual periods stop early or are disrupted, and is usually often seen in younger women along with anorexia nervosa or athletes who physically train in a very large level.
  • Milk allergy or lactose intolerance— Occurs when the entire body cannot digest the sugar in milk products, lactose, or the proteins in milk, casein or whey. Lactose intolerance can be genetic or acquired (not consuming lactose in the extensive may decrease the efficiency of lactase enzyme)


Too much calcium supplement in the blood is called hypercalcemia. The Upper Limit (UL) for calcium is 2, 500 mg daily through food and supplements. People over the age of 50 should not take more than two, 000 magnesium daily, especially from dietary supplements, as this can increase risk of some conditions like kidney stones, prostate cancer, and constipation. Some research has shown that in certain people, calcium can accumulate in blood vessels along with long-term higher doses plus cause heart problems. Calcium is also a large mineral that can block the absorption of other minerals like iron and zinc.

Symptoms of hypercalcemia:

  • Weakness, fatigue
  • Nausea, vomiting
  • Shortness of breath
  • Chest pain
  • Heart palpitations, irregular coronary heart rate

Did A person Know?

Certain nutrients plus medications may increase your need for calcium supplements because they either lower the particular absorption associated with calcium inside the gut or cause more calcium to be excreted in the urine. These include: corticosteroids (example: prednisone), excess sodium in the diet, phosphoric acid such as found in dark cola sodas, excess alcohol, and oxalates (see Are anti-nutrients harmful? ).

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The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or even delay in seeking it because of something you have read on this website. The Nutrition Source does not recommend or endorse any kind of products.

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