Many people are aware that calcium is an important mineral involved in bone growth and development. However, in addition to bone health, calcium is also involved in many cellular functions such as muscle contraction, blood clotting and hormone release.
When there is a prolonged decline in blood calcium levels, calcium is released from storage, mainly from the bones, leading to a condition called osteoporosis, which is characterized by bone weakness. Dietary deficiency can also lead to rickets in children.
Other conditions associated with calcium deficiency include blood clotting disorders, high blood pressure, and cardiac arrhythmias (irregular heartbeats).
Why People Take Calcium Supplements
According to experts, many people in the US do not get enough calcium in their diet. Although calcium is abundantly found in foods such as dairy products, green vegetables, fish and fortified juices and cereals, some people are at risk for calcium deficiency, including:
- Postmenopausal women
- People with food allergies or lactose intolerance
- People older than 51 years old
- Pregnant and breastfeeding women
- Vegetarians, vegans, and those on strict diets
- Cancer patients
- People on prolonged intake of medications like corticosteroids and chemotherapy
Any of these groups may need to take calcium supplements.
It’s interesting to note that, people also take calcium in the form of antacids and as treatment for high levels of potassium, phosphorus, and magnesium in the blood.
The mineral has also been found to help prevent or control hypertension (high blood pressure), reduce PMS (premenstrual syndrome) symptoms, as well as prevent certain cancers.
How Much Calcium Do We Need?
According to the Institute of Medicine, the recommended daily intake of calcium according to age is:
- 1-3 years: 700 milligrams (mg)
- 4-8 years: 1,000 mg
- 9-18 years: 1,300 mg
- 19-50 years: 1,000 mg
- 51-70 years: 1,200 mg for women and 1,000 mg for men
- 71 and older: 1,200 mg
Although many people are able to obtain enough calcium from a healthy, balanced diet, many Americans lack the mineral. Girls aged 9-19 are at particular risk of too little calcium.One of the reasons adequate calcium intake is critical at an early age has to do with bone development. Peak bone mass is achieved by the age of 30 and declines after that. Therefore it is important to have sufficient calcium intake when you are young.
Calcium supplements may be also prescribed for other conditions with the following recommended daily doses:
- Pregnant or lactating women, under 19 years: 1300 mg
- Pregnant or lactating women, 19-50 years: 1000 mg
- For prevention of osteoporosis: 1-1.6 grams
- Osteoporosis treatment: 1200 mg
- For premenopausal women over 40: 1 gram.
- For premenstrual syndrome (PMS): 1-1.2 grams
- For high blood pressure: 1-1.5 grams
- For preventing high blood pressure during pregnancy (pre-eclampsia): 1-2 grams calcium carbonate.
- For preventing colorectal cancer and recurrent colorectal benign tumors: 1200-1600 mg
- For high cholesterol: 1200 mg with or without vitamin D 400 IU
How to Take Calcium Supplements
The most commonly used calcium preparations are calcium citrate and calcium carbonate. Calcium carbonate supplements, which contain 40% elemental calcium, are the best tolerated and least expensive.
Calcium citrate supplements, which contain 21% elemental calcium, are better absorbed when people have problems producing enough stomach acid or are taking medications that limit acid production.
Other preparations, such as calcium lactate, calcium gluconate, coral calcium, calcium plus magnesium or calcium plus vitamin D may also be used.
Calcium supplements are available in tablets, capsules, chewable forms, liquids, and powders. People who have trouble swallowing pills may take a chewable or liquid calcium supplement.
To take an adequate amount of calcium, one must consider how much calcium they are obtaining from their diet and how much additional calcium they may need in the form of supplements. Calculating optimal calcium supplementation this way is done to avoid taking more than what is normally needed.
To calculate dietary calcium, use an estimate of 300 mg per day from non-dairy foods and 300 mg per cup of milk or fortified orange juice.
The average dose for supplemental calcium is between 1000-1300 mg of calcium per day.
Calcium supplements are best absorbed in doses of 500 mg, so if one needs 1000 mg/day it is recommended that the dose is split into two. Although calcium carbonate supplements are best taken with meals for better absorption, calcium citrate preparations do not need to be taken with food.
Calcium and Vitamin D
It is worthwhile to note that bone absorption of calcium is facilitated by the presence of adequate amounts of vitamin D. Without this vitamin dietary or supplemental calcium will not be efficiently absorbed.
Although vitamin D is called the ‘sunshine vitamin’ because the skin produces it when exposed to sunlight, many people do not receive enough of it. Therefore, to prevent osteoporosis, especially in people who don’t get enough sunlight or eat enough foods with vitamin D, taking calcium with vitamin D may be beneficial.
The National Academy of Sciences recommends that individuals from age 1 to 70 take 600 international units (IU) of vitamin D daily, and 800 IU after age 70. However, more recent studies have shown that doses of 800-1200 IU may be necessary to prevent osteoporosis.
Calcium Food Calculator. WebMD. http://www.webmd.com/diet/calcium-food-calculator/calcium-supplements
- Vitamins and Supplements Lifestyle Guide: Calcium. WebMD. http://www.webmd.com/vitamins-and-supplements/lifestyle-guide-11/supplement-guide-calcium
- Calcium. WebMD. http://www.webmd.com/vitamins-supplements/ingredientmono-781-CALCIUM.aspx?activeIngredientId=781&activeIngredientName=CALCIUM&source=2&tabno=7
- Calcium and calcium supplements: Achieving the right balance. Mayo Clinic. http://www.mayoclinic.com/health/calcium-supplements/MY01540/