Calcium is a vital mineral. Your body uses it to build strong bones and teeth. Calcium is also needed for your heart and other muscles to function properly. When you don’t get enough calcium, you increase your risk of developing disorders like osteoporosis, osteopenia, and calcium deficiency disease (hypocalcemia). Children who don’t get enough calcium may not grow to their full potential adult height.
You should consume the recommended amount of calcium per day through the food you eat, supplements, or vitamins.
Many people are at increased risk for calcium deficiency as they age. This deficiency may be due to a variety of factors, including:
- poor calcium intake over a long period of time, especially in childhood
- medications that may decrease calcium absorption
- dietary intolerance to foods rich in calcium
- hormonal changes, especially in women
- certain genetic factors
It is important to ensure proper calcium intake at all ages.
For children and teenagers, the recommended daily allowances for calcium are the same for both sexes. According to the National Institutes of Health (NIH), the daily allowances are:
|Age group||Daily recommended dietary allowance (RDA)|
|Children, 9–18 years||1,300 mg|
|Children, 4–8 years||1,000 mg|
|Children, 1–3 years||700 mg|
|Children, 7–12 months||260 mg|
|Children, 0–6 months||200 mg|
According to the U.S. government’s dietary guidelines, calcium requirements for adults are:
|Group||Daily recommended dietary allowance (RDA)|
|Women, 71 years and up||1,200 mg|
|Women, 51–70 years||1,200 mg|
|Women, 31–50 years||1,000 mg|
|Women, 19–30 years||1,000 mg|
|Men, 71 years and up||1,200 mg|
|Men, 51–70 years||1,000 mg|
|Men, 31–50 years||1,000 mg|
|Men, 19–30 years||1,000 mg|
Women need to increase their calcium intake earlier in life than men, starting in middle age. Meeting the necessary calcium requirement is particularly important as a woman approaches menopause.
Women in menopause should also increase their calcium intake to reduce the risk of osteoporosis and calcium deficiency disease. The decline in the hormone estrogen during menopause causes a woman’s bones to thin faster.
The hormone disorder hypoparathyroidism may also cause calcium deficiency disease. People with this condition don’t produce enough parathyroid hormone, which controls calcium levels in the blood.
Other causes of hypocalcemia include malnutrition and malabsorption. Malabsorption is when your body can’t absorb the vitamins and minerals you need from the food you eat. Additional causes include:
- low levels of vitamin D, which makes it harder to absorb calcium
- medications, such phenytoin, phenobarbital, rifampin, corticosteroids, and drugs used to treat elevated calcium levels
- hypermagnesemia and hypomagnesemia
- septic shock
- massive blood transfusions
- renal failure
- certain chemotherapy drugs
- “Hungry bone syndrome,” which may occur after surgery for hyperparathyroidism
If you miss your daily dose of calcium, you won’t become calcium deficient overnight. But it’s still important to make an effort to get enough calcium every day, since the body uses it quickly. Vegans are more likely to become calcium deficient quickly because they don’t eat calcium-rich dairy products.
Calcium deficiency won’t produce short-term symptoms because the body maintains calcium levels by taking it directly from the bones. But long-term low levels of calcium can have serious effects.
Early stage calcium deficiency may not cause any symptoms. However, symptoms will develop as the condition progresses.
Severe symptoms of hypocalcemia include:
- confusion or memory loss
- muscle spasms
- numbness and tingling in the hands, feet, and face
- muscle cramps
- weak and brittle nails
- easy fracturing of the bones
Calcium deficiencies can affect all parts of the body, resulting in weak nails, slower hair growth, and fragile, thin skin.
Calcium also plays an important role in both neurotransmitter release and muscle contraction. So, calcium deficiencies can bring on seizures in otherwise healthy people.
If you start experiencing neurological symptoms like memory loss, numbness and tingling, hallucinations, or seizures, make an appointment to see your doctor as soon as possible.
Contact your doctor if you have symptoms of calcium deficiency disease. They’ll review your medical history and ask you about family history of calcium deficiency and osteoporosis.
If your doctor suspects calcium deficiency, they’ll take a blood sample to check your blood calcium level. Your doctor will measure your total calcium level and your albumin level. Albumin is a protein that binds to calcium and transports it through the blood. Sustained low calcium levels in your blood may confirm a diagnosis of calcium deficiency disease.
Normal calcium levels for adults can range from 8.8 to 10.4 milligrams per deciliter, according to the Merck Manual. You may be at risk for calcium deficiency disease if your calcium level is below 8.8 mg/dL. Children and teens typically have higher blood calcium levels than adults.
Neonatal hypocalcemia occurs in infants soon after birth. Most neonatal hypocalcemia occurs within the first two days after birth. But late onset hypocalcemia can occur three days after birth or later.
Risk factors for infants include being small for their age and maternal diabetes. Late onset hypocalcemia is most often caused by drinking cow’s milk or formula with too much phosphate.
Symptoms of neonatal hypocalcemia include:
- poor feeding
- apnea, or slowed breathing
- tachycardia, or a faster-than-normal heartbeat
Diagnosis is made by testing an infant’s blood for the total calcium level or ionized calcium level. The infant’s glucose level will also be tested to rule out hypoglycemia.
Treatment typically involves giving intravenous calcium gluconate followed by several days of oral calcium supplements.
Calcium deficiency is usually easy to treat. It typically involves adding more calcium to your diet.
Do not self-treat by taking a lot of calcium supplements. Taking more than the recommended dose without your doctor’s approval can lead to serious issues like kidney stones.
Commonly recommended calcium supplements include:
- calcium carbonate, which is the least expensive and has the most elemental calcium
- calcium citrate, which is the most easily absorbed
- calcium phosphate, which is also easily absorbed and does not cause constipation
Calcium supplements are available in liquid, tablet, and chewable forms.
It is important to note that some medications could interact negatively with calcium supplements. These medications include:
- blood pressure beta-blockers like atenolol, which may decrease calcium absorption if taken within 2 hours of taking calcium supplements
- antacids containing aluminum, which may increase blood levels of aluminum
- cholesterol-lowering bile acid sequestrants such as colestipol, which may decrease calcium absorption and increase the loss of calcium in the urine
- estrogen medications, which can contribute to an increase in calcium blood levels
- digoxin (high calcium levels can increase digoxin toxicity)
- diuretics, which can either increase calcium levels (hydrochlorothiazide) or decrease calcium levels in the blood (furosemide)
- certain antibiotics such as fluoroquinolones and tetracyclines, whose absorption can be decreased by calcium supplements
Sometimes diet changes and supplements aren’t enough to treat a calcium deficiency. In this case, your doctor may want to regulate your calcium levels by giving you regular calcium injections.
You can expect to see results within the first few weeks of treatment. Severe cases of calcium deficiency disease will be monitored at one- to three-month intervals.
Complications from calcium deficiency disease include eye damage, an abnormal heartbeat, and osteoporosis.
Complications from osteoporosis include disability, spinal fractures or other bone fractures, and difficulty walking. If left untreated, calcium deficiency disease could eventually be fatal.
You can prevent calcium deficiency disease by including calcium in your diet every day.
Be aware that foods high in calcium, such as dairy products, can also be high in saturated fat and trans fat. Choose low-fat or fat-free options to reduce your risk of developing high cholesterol and heart disease.
You can get one-fourth to one-third of your RDA of calcium in a single serving of some milks and yogurts. According to the United States Department of Agriculture (USDA), other calcium-rich foods include:
|Food||Approximate serving size||Amount of calcium per serving|
|Sardines (in oil)||3.75 oz.||351 mg|
|Salmon (pink, canned, with bones)||3 oz.||183 mg|
|Fortified tofu (regular, not firm)||1/3 cup||434 mg|
|Edamame (frozen)||1 cup||71–98 mg|
|White beans||1 cup||161 mg|
|Collard greens (cooked)||1 cup||268 mg|
|Broccoli (cooked)||1 cup||62 mg|
|Figs (dried)||5 figs||68 mg|
|Fortified orange juice||1 cup||364 mg|
|Wheat bread||1 slice||36 mg|
While meeting your calcium requirement is very important, you also want to make sure you’re not getting too much. According to the Mayo Clinic, upper limits of calcium intake for adults are:
- 2,000 mg per day for men and women 51 years of age and up
- 2,500 mg per day for men and women 19 to 50 years of age
You might want to supplement your diet by taking a multivitamin. Or your doctor may recommend supplements if you’re at high risk for developing a calcium deficiency.
Multivitamins may not contain all of the calcium you need, so be sure to eat a well-rounded diet. If you’re pregnant, take a prenatal vitamin.
Vitamin D is important because it increases the rate calcium is absorbed into your blood. Ask your doctor how much vitamin D you need.
To increase your calcium intake, you can add food rich in vitamin D to your diet. These include:
- fatty fish like salmon and tuna
- fortified orange juice
- fortified milk
- portobello mushrooms
As with calcium-rich dairy products, some vitamin D-rich dairy products can also be high in saturated fat.
Sunlight triggers your body to make vitamin D, so getting regular exposure to the sun can also help boost your vitamin D levels.
In addition to maintaining healthy calcium and vitamin D levels, there are certain lifestyle changes you can make to promote bone health. These include maintaining a healthy body weight, exercising regularly, and restricting tobacco use and alcohol intake.