WHO SHOULD TAKE CALCIUM SUPPLEMENTS?

Calcium is an essential mineral for the human body. It helps form and protects teeth and bones. Appropriate calcium levels over a lifetime can help prevent osteoporosis, sometimes called "thin bones."
Most people get enough calcium in their daily diet. Dairy foods, green leafy vegetables, and calcium-fortified foods have high calcium levels. For example, 1 cup (237 ml) of milk or yogurt (has 300 mg of calcium). Older women and men may need extra calcium to prevent the weakening of the bones (osteoporosis).
Your health care provider will tell you if you need to take additional calcium supplements. The decision to take extra calcium should be based on the risks and benefits of doing so.

TYPES OF CALCIUM SUPPLEMENTS

Calcium forms include:

Calcium carbonate. Over-the-counter antacid products contain calcium carbonate. Each pill or chew supplies 200 mg or more of calcium. This form of calcium must be taken with meals. There is unusual calcium carbonate, amorphous calcium carbonate, and it should be eaten on an empty stomach, allowing it to be absorbed better.
Calcium citrate. It is well absorbed on an empty or full stomach. People with low stomach acid levels (a condition common in people over 50) absorb calcium citrate more easily than calcium carbonate.
Other forms include calcium gluconate, calcium lactate, and calcium phosphate. Most contain less calcium than the carbonate and citrate forms and provide no benefit.

HOW TO TAKE EXTRA CALCIUM

Follow your provider's advice about how much extra calcium you need.
Increase the dose of your calcium supplement slowly. For example, your provider may recommend starting with just 500 mg daily for a week and gradually adding more calcium.
Try to spread the extra calcium throughout the day. DO NOT take more than 500 mg at a time. Take calcium throughout the day:
Allows more calcium to be absorbed
Reduces side effects such as gas, bloating, and constipation

The total amount of calcium adults need each day from food and calcium is
19 to 50 years: 1,000 mg/day
51 to 70 years: men - 1,000 mg/day; women - 1,200 mg/day
71 years and older: 1,200 mg/day
Vitamin D is needed to help the body absorb calcium. You can get vitamin D from food and by exposing your skin to sunlight. Ask your provider if you need to take a vitamin D supplement. Some forms of calcium supplements also contain vitamin D.

SECONDARY EFFECTS AND SAFETY

DO NOT take more than the recommended amount of calcium without your provider's approval.

Try the following if you experience side effects from taking extra calcium:

Drink more fluids.
Eat high-fiber foods.
Try another form of calcium if dietary changes don't help.
Always tell your provider and pharmacist if you are taking extra calcium. Calcium supplements can change the way your body absorbs some medications. This includes certain antibiotics and iron pills.
Be aware of the following:
Taking extra calcium over a long periods of time increases the risk of kidney stones in some people.
Too much calcium can prevent the body from absorbing iron, zinc, magnesium, and phosphorus.
Antacids have other ingredients like sodium, aluminum, and sugar. Ask your provider if it is OK for you to use antacids as a calcium supplement.

Bone health benefits and drawbacks of excessive calcium intake

Current evidence on the relationship between calcium intake, fracture risk, and the safety of calcium supplements.

Presentation of a case

A healthy 62-year-old woman visits her doctor for a routine checkup. She has no history of fractures, but she wants to know if she has osteoporosis because her mother had a hip fracture at age 72. She exercises regularly, and since her menopause, at age 54, she takes 1,000 mg of calcium carbonate over the counter three times a day. This dose provides you with 1,200 mg of elemental calcium/day. In addition, she follows a healthy diet with several servings of fruits and vegetables, and she consumes 8 ounces of low-fat yogurt and a glass of low-fat milk almost daily. However, since she has heard that calcium supplements may increase the risk of cardiovascular disease, she wants the doctor's opinion on whether she should continue taking them.

Clinical problem

Physicians and patients alike can be confused by inconsistent and sometimes conflicting advice about how much calcium needs to be consumed to reduce fracture risk and, in particular, whether calcium supplementation is necessary. Prolonged calcium deficiency can predispose to osteoporosis, but many people mistakenly believe that postmenopausal bone loss and associated increased risk of fracture can be prevented using calcium supplements. Although some remain at risk of calcium deficiency, others may receive a higher than recommended daily dose, particularly those taking calcium supplements.

The complex and incompletely understood interaction between calcium intake and vitamin D implies a better understanding of the benefits and risks of each of them separately. For example, a recent randomized study showed that even high doses of vitamin D3 (4,800 IU/day) did little to improve calcium absorption (6% increase) among postmenopausal women with low 25-dihydroxy vitamin D levels. In addition, numerous clinical studies have studied the combination of calcium with vitamin D in various doses. Still, there are fewer studies of the effects of calcium alone on the skeleton.

Strategies and evidence.

calcium requirements

More than 98% of body calcium decreases in the skeleton. Bone is a storehouse for calcium. It occurs in large quantities in the organic bone matrix and provides strength and rigidity to the skeleton. Due to forced loss through urine, sweat, and feces, insufficient calcium intake can affect the physiological process.

Important Clinical Concepts

Calcium supplements and fracture prevention

• The recommended daily calcium intake for women ages 19 to 50 and men ages 19 to 70 is,000 mg/day; women >50 years and men >70 years need 1,200 mg/day. Calcium intake of more than 2,500 mg/day (2,000 mg/day in those over 50 years of age) should be avoided.

• Adequate calcium intake is essential for bone health at all ages. Conversely, inadequate calcium intake is common in adults, especially in men and women >70 years, and is associated with increased bone loss and fracture risk.
• The preferred approach to ensure adequate calcium intake is to consume calcium-rich foods and beverages. There is insufficient evidence to recommend the routine use of calcium supplements in community-dwelling adults, but they should be considered when dietary intake is inadequate.
• Calcium supplements usually have few adverse effects; although constipation and bloating are common, the appearance of nephrolithiasis is rare.
• Recent studies have highlighted the possibility that calcium supplements increase cardiovascular risk, but the findings are inconsistent and inconclusive.

Primarily based on studies of calcium balance in people <50 years of age and the knowledge that bone loss accelerates in menopause and older age, the Institute of Medicine (IOM) has produced guidance regarding daily calcium intake according to sex and age.
The recommended calcium intake and the calcium content of various foods and supplements are expressed in milligrams of elemental calcium. Different supplement formulations provide different amounts of elemental calcium. The recommended dietary intakes are based on the requirements for a healthy population. The highest recommended doses are primarily decided on the risk for nephrolithiasis. It was observed in studies of calcium supplementation in postmenopausal women. Calcium absorption is increased in pregnant and lactating women, but the recommended calcium intake for these women does not differ from that for other women in the same age group.

In a study of an adult population in the United States, the dietary intake of elemental calcium varied according to the age of the group, but the average was 900 to 1,200 mg in men and 750 to 850 mg in women; the lowest intake was observed in men and women >70 years. More than 70% of the calcium in the diet comes from dairy products.
To calculate a person's daily calcium intake, one can assume that most adults consume about 300 mg of calcium per day from other non-dairy foods and then calculate the daily intake total by adding the daily intake of dairy products.
Calcium supplements are common; Prevalence surveys have shown that 43% of US adults (and almost 70% of postmenopausal women) take calcium supplements regularly. However, despite the frequent use of these supplements, many adults in this country, particularly postmenopausal women, do not consume the recommended 1,000 to 1,200 mg/day of elemental calcium, and few consume more than the upper recommended level (2,000 to 2,500 mg/day).

Dietary calcium versus calcium supplements

In general, calcium-rich foods and beverages, particularly dairy products, are the preferred source of calcium because they are widely available and, except for lactose intolerance, have few adverse effects.
Some evidence indicates that calcium from specific food sources such as broccoli and Brussels sprouts (kale) is absorbed in a higher rate than calcium from supplements. Although data based on clinical outcomes (fractures) are lacking, physiological studies have shown no material differences in the metabolic actions of calcium from food compared to calcium from supplements. Therefore, whether or not to receive calcium supplements depends on whether dietary calcium intake is adequate and the balance between supplementation's potential benefits and harms.
Calcium supplements are available over the counter, and each tablet's total calcium salt and elemental calcium content is expressed in milligrams. The daily dose of calcium to meet the requirement must be referred to as the amount of elemental calcium. The most commonly used preparations are purified calcium carbonate, calcium citrate, and, to a lesser extent, calcium lactate and gluconate; preparations differ in the amount of elemental calcium they provide.

Calcium carbonate provides a relatively high elemental calcium content (40%) and is the cheapest and most widely available. However, compared with other calcium supplements, calcium carbonate is the one that can cause constipation and meteorism the most; therefore, it must be taken with meals since gastric acidity is necessary for sufficient absorption.
Compared with carbonated calcium, citrate provides less elemental calcium (21%) but is reasonable for patients with undesirable gastrointestinal symptoms; It can be taken with or without food since absorption does not depend on gastric acidity. If a daily intake of elemental calcium >500 mg is required, it is recommended to divide the doses to improve absorption and minimize gastrointestinal side effects.

Potential Benefits of Calcium Intake

Postmenopausal and age-related bone loss, which is associated with an increased risk of fracture, occurs when there is a net loss of bone calcium due to an imbalance between bone resorption and formation. Although postmenopausal bone loss is primarily related to hypoestrogenemia, age-related bone loss in both men and women is determined by genetic, hormonal, and other factors. Observational studies indicate that bone loss and fracture risk increase when calcium intake is <700 to 800 mg/day. In contrast, the effect of additional calcium intake on bone loss in people without calcium deficiency is less clear and probably negligible.

Many studies have evaluated the benefits of calcium supplementation in fracture prevention, but most of them, such as the Women's Health Initiative (WHI) Calcium/Vitamin D Supplementation trial, included vitamin D as part of the intervention and did not preferentially enroll people with low calcium intake.

How to choose calcium supplements

When considering calcium supplements, consider the following factors:

Calcium amounts
Elemental calcium is important because it is the actual amount of calcium in the supplement. It is what the body absorbs for bone growth and other health benefits. The facts label on calcium supplements helps determine how much calcium is in a serving. For example, calcium carbonate is 40% elemental calcium, so 1,250 milligrams (mg) of calcium carbonate contains 500 mg of elemental calcium. Be sure to note the serving size (number of tablets) to determine how much calcium is in a serving.