By Dr Ahmed Nasr
Calcium and Calcium Supplements
Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat.
About 99% of the calcium in our bodies is in our bones and teeth.
Calcium and diet
Your body doesn't produce calcium, so you must get it through other sources. Calcium can be found in a variety of foods, including:
- Dairy products, such as cheese, milk and yogurt
- Dark green leafy vegetables, such as broccoli and kale
- Fish with edible soft bones, such as sardines and canned salmon
- Calcium-fortified foods and beverages, such as soy products, cereal and fruit juices, and milk substitutes
To absorb calcium, your body also needs vitamin D. A few foods naturally contain small amounts of vitamin D, such as canned salmon with bones and egg yolks. You can also get vitamin D from fortified foods and sun exposure. The RDA for vitamin D is 600 international units (15 micrograms) a day for most adults.
How much calcium you need depends on your age and sex?
- 0–6 months: 200 milligrams (mg)
- 7–12 months: 260 mg
- 1–3 years: 700 mg
- 4–8 years: 1,000 mg
- 9–18 years: 1,300 mg
- 19–50 years: 1,000 mg
- 51–70 years: 1,000 mg for males and 1,200 mg for females
- 71 years and above: 1,200 mg
Pregnant and breastfeeding women require 1,000–1,300 mg depending on age.
A doctor may recommend additional calcium for people who:
- have started menopause
- stop menstruating due to anorexia nervosa or excessive exercise
- have lactose intolerance or a cow’s milk allergy
- follow a vegan diet
Calcium deficiency: The following conditions or lifestyle habits may result in low calcium levels, also known as hypokalemia:
- bulimia, anorexia, and some other eating disorders.
- overconsumption of magnesium
- long-term use of laxatives
- prolonged use of some medicines, such as chemotherapy or corticosteroids
- chelation therapy used for metal exposure
- lack of parathyroid hormone
- people who eat a lot of protein or sodium may excrete calcium.
- some cancers
- high consumption of caffeine, soda, or alcohol
- some conditions, such as celiac disease, inflammatory bowel disease, Crohn’s disease, and some other digestive diseases
- some surgical procedures, including removing the stomach
- kidney failure
- vitamin D deficiency
- phosphate deficiency
The body eliminates some calcium in sweat, urine, and feces. Foods and activities that encourage these functions may reduce the levels of calcium in the body.
Calcium supplements: A doctor may recommend calcium supplements for people who have a calcium deficiency.
People who use calcium supplements should:
- check first with their doctor whether they need supplements
- follow the dosage the doctor recommends
- take the supplement with food for best absorption and to minimize possible adverse effects
- consume the supplements at intervals, usually two or three times a day
Many calcium supplements also contain vitamin D. Vitamin D encourages the synthesis of proteins in the body and helps the body absorb calcium. Magnesium also plays a role in strengthening bones, and calcium supplements may also contain magnesium.
Types of calcium supplements
There are different types of supplements. A doctor can recommend the best option. This will depend on the individual’s needs and preferences, any medical conditions they have, and whether they are taking any medications.
Elemental calcium is the pure mineral, but calcium in its natural form exists with other compounds.
Common calcium supplements may be labeled as:
- Calcium carbonate (40 percent elemental calcium)
- Calcium citrate (21 percent elemental calcium)
- Calcium gluconate (9 percent elemental calcium)
- Calcium lactate (13 percent elemental calcium)
The two main forms of calcium supplements are carbonate and citrate. Calcium carbonate is cheapest and therefore often a good first choice. Other forms of calcium in supplements include gluconate and lactate.
In addition, some calcium supplements are combined with vitamins and other minerals. For instance, some calcium supplements may also contain vitamin D or magnesium. Check the ingredient list to see which form of calcium your calcium supplement is and what other nutrients it may contain. This information is important if you have any health or dietary concerns.
More isn't always better: Too much calcium has risks
Dietary calcium is generally safe, but more isn't necessarily better, and excessive calcium doesn't provide extra bone protection.
If you take calcium supplements and eat calcium-fortified foods, you may be getting more calcium than you realize. Check food and supplement labels to monitor how much total calcium you're getting a day and whether you're achieving the RDA but not exceeding the recommended upper limit. And be sure to tell your doctor if you're taking calcium supplements.