Most Americans have a strong mental association between drinking milk and having strong bones, thanks to clever advertising.
Those old TV commercials weren’t wrong – dairy is a good dietary source of calcium, which is important for strong bones. But many of us don’t really understand how important calcium is for our bodies, and all the things it does.
About Calcium
Calcium is the single most abundant mineral in the human body. And nearly all of it – 99% – is stored in our bones and teeth, which are literally made out of calcium.
But the remaining 1% is vital to perform important tasks in the blood, where calcium helps to maintain heart rhythm and when necessary, form blood clots. It can also be found in muscles, which need calcium to contract, and in the nerves, which use calcium to transmit signals.
In addition, calcium also plays a role in the function of many enzymes (which support routine chemical reactions in the cells).
What causes Calcium deficiency
Although calcium is the structural material that bones are made of, the mineral is not passively stored there. Rather, the bones act like a bank where calcium is deposited and withdrawn as needed. The body doesn’t produce calcium, so it needs to get it from external sources.
When a person doesn’t consume enough calcium for it to fulfill its critical tasks in the body, calcium is then taken from the bones. That’s good news for nerve and muscle functions, but it means that even strong bones can eventually weaken as a result of calcium deficiency.
At what age does bone loss begin?
Beginning at around age 30, bone loss tends to speed up for all individuals, increasing the risk of osteoporosis.
However, for women, the drop in estrogen production after menopause decreases calcium absorption and further increases bone loss, putting older women at higher risk of deficiency.
Children with calcium deficiency can develop rickets, a condition in which cartilage does not mineralize normally as a child grows, leading to irreversible changes in skeletal structure.
How Calcium level affects other health conditions
The connection between bone health and calcium levels is clear. Studies on calcium and other health conditions are less conclusive, but higher calcium consumption during pregnancy has been associated with reduced risk of preeclampsia and hypertensive disorders, and some studies find a correlation between higher calcium and reduced risk of certain cancers.
Although calcium buildup in the heart is an indicator of heart disease, coronary artery calcification is not associated with calcium intake.
Similarly, the bone spurs associated with arthritis are made from calcium, but rather than reducing calcium intake, arthritis patients can benefit from calcium supplementation.
Problems caused by excess Calcium
Having too much calcium in your body can also cause health problems. Hypercalcemia (high blood calcium level) and hypercalciuria (excess urinary calcium level) can cause:
- poor muscle tone
- kidney disease
- constipation
- nausea
- weight loss
- fatigue
- polyuria (excessive urination)
- hypophosphatemia (low phosphate levels)
- heart arrhythmias, and
- a higher risk of mortality from cardiovascular disease.
How much Calcium do you need?
The right amount of calcium intake varies by age and sex. The National Institutes of Health recommend consuming the following number of milligrams of calcium per day:
| Life Stage | Recommended Amount |
| Birth to 6 months | 200 mg |
| Infants 7–12 months | 260 mg |
| Children 1–3 years | 700 mg |
| Children 4–8 years | 1,000 mg |
| Children 9–13 years | 1,300 mg |
| Teens 14–18 years | 1,300 mg |
| Adults 19–50 years | 1,000 mg |
| Adult men 51–70 years | 1,000 mg |
| Adult women 51–70 years | 1,200 mg |
| Adults 71 years and older | 1,200 mg |
| Pregnant and breastfeeding teens | 1,300 mg |
| Pregnant and breastfeeding women | 1,000 mg |
About testing for Calcium levels
A metabolic blood panel tests for different compounds in the bloodstream, including calcium. But health care providers usually only test for calcium when they’re concerned about diseases that can affect calcium levels, even if a patient is already taking in enough calcium.
More often, a health care provider will focus on the patient’s calcium intake as they age, because a healthy, balanced diet is essential to help prevent the onset of osteoporosis.
Taking Calcium supplements
Although it’s easy to get enough calcium from eating a healthy diet, many Americans actually don’t consume enough extra calcium.
Over 40% of the U.S. population don’t get enough calcium from diet alone. And even when supplements are added, the demographics most frequently found to have calcium deficiency are:
- Female adolescents ages 12-19
- Older women over 60
- Non-Hispanic Blacks and
- Non-Hispanic Asians
Supplements are recommended for these people who are at risk of calcium deficiency, plus anyone who is:
- pregnant
- postmenopausal
- vegan, or
- lactose-intolerant
When taking calcium supplements, it’s better to take small doses more frequently, because the body doesn’t absorb calcium as well with large doses.
What foods are a good source of Calcium?
Dairy – including yogurt, milk, and cheese – is one of the best dietary sources of calcium, and accounts for 72% of Americans’ calcium intake.
Another good source of calcium is tinned fish, such as sardines and anchovies, that contain edible bones.
Dark green vegetables, including kale, spinach, chard, bok choy, and collard greens are high in calcium, but in a form that may not be absorbed as efficiently. Sauteeing or steaming dark greens can help increase calcium absorption.
Grains, although relatively low in calcium per serving, are still a significant source of dietary calcium because they make up a large portion of most people’s diets.
Many other foods are fortified with calcium, including cereals, tofu, and beverages such as orange juice and milk substitutes.
Foods with added calcium are especially valuable for vegetarians and vegans to up their intake.
Can added Calcium interact with medications?
Calcium may interact with certain antibiotics and medications used in the treatment of thyroid disorders, bipolar disorder, and HIV.
If you’re receiving care for any of these conditions, talk to your WWMG primary care provider about possible interactions.
Where to get your Calcium levels tested
If you’re concerned about calcium deficiency, make an appointment with your WWMG primary care provider to get your levels tested. They’ll provide valuable guidance, education and support to keep you healthy now and in the years to come.